# Sticky  Electric cooling fan and controller, done!



## TheRepairMan (Jun 30, 2009)

7/08/2014 Update: Derale has upgraded their controller... see here...http://derale.com/products/electric...fan-clutch2013-10-18-11-52-51928758585-detail










Well guys, I promised I was going to do this mod. So I finally got it done. A warning ahead... this will be a pretty long write up, and photo intense. And, here's a link to a file from Derale Performance Products you all need to read along with my instructions if you are considering this cooling fan mod to any vehicle. http://derale.com/images/stories/virtuemart/product/pdfs/16759.pdf

I had originally planned to do it during the timing chain job, but since I use the truck almost daily I decided to break them up into two jobs. Okay, first off, this is a 94 D21 2.4, std. trans, 2wd with AC, and just over 106,000 miles on the clock. No other particular concerns ...in other words, I'm not doing this mod to try to repair a problem with the truck, just to make some improvements in the heating and cooling systems. It may even just be a wash, but it seems nearly everything built has an electric fan on it now to make it more efficient, so why not our trucks, if we want.

There are pros and cons I guess to having this system take the place of your stock mechanical fan and fan clutch, so I'm not going to tell anyone it's worth the time, money, effort, or risk ...but I don't mind being the test rat. I'll be looking for better cold weather warm up (more interior heat sooner), better fuel mileage, and a slightly cooler running engine during hotter seasons. I'll report my long term findings back here as the miles add up.

Here goes ...the first thing was just to remove the 4 stock cooling fan nuts and store the old fan away.Next, the upper radiator hose at the radiator along with four screws that hold the fan shroud on to the radiator.

Aligning the new 16" cooling fan into position in the shroud was easy enough, so I drilled four holes and bolted it down. I had to cut a small relief in the lower section of the fan shroud for the cooling fan wire and connector.

Fan and radiator shroud removed. (I apologize about the bluish tint of the first photos. I had a color temperature setting way off in the camera.)









I chose to remove the fan old stock fan mounting studs and replace them with some stainless bolts and lock washers. It already looks cooler!










Here's the new fan mounted in the shroud (just sitting up in the truck bed for photo purposes). This is the engine side. I decided against attaching the fan directly to the radiator to prevent any unwanted stress on the core tubes from the weight or any vibration that might be transfered. This was the best choice.









Here's the radiator side.









And, with the new fan/shroud assy. mounted to the radiator. If you look closely you can see there's about 1/2" clearance between the fan motor and the waterpump hub and pulley. That's more than enough. 


















I'll follow up with more details as I have time. The next steps are installing the adjustable electric fan controller.

And here's a link to the one I used... http://derale.com/products/electric...fan-clutch2013-10-18-11-52-51928758585-detail


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## SPEEDO (Jun 9, 2003)

I have been wanting to do that to mine for a long time... I like the way you are doing it, clean install!


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## TheRepairMan (Jun 30, 2009)

SPEEDO said:


> I have been wanting to do that to mine for a long time... I like the way you are doing it, clean install!


Thanks! So far so good.

Here's a pic of the bottom of the electric adjustable cooling fan controller. Connecting everything was actually easier than installing the aftermarket stereo. Note there are two power circuits for dual fans. I only used one of them, the ORANGE wire, and oddly enough, on my controller, it had an inline fuse installed, and the blue one didn't. I think they meant to put it in the RED positive (+) lead to the battery, but I just went ahead and installed an extra one in line to the hot wire on the battery to protect the entire circuit. You can't skip that step!










This should look familiar. You are going to unbolt the relay box and the other two relays, and flip them upside down for a minute to gain access to the two signal wires to tap into. The pic was taken after mine was completed. Note an extra conduit going under the front end of the relay box.














-R


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## TheRepairMan (Jun 30, 2009)

! Just a strong word of caution before we continue. All of the cooling system electrical connections are critical to the proper operation of the electric adjustable cooling fan! Taking short cuts as well as not properly testing the integrity of the entire installation could lead to a catastrophic engine failure!

If you have any doubt's about completing this installation properly, then DON'T attempt it! Period!

Okay, so if you are going ahead, by now you've got the fan installed, and you know which direction the wires are going to run, so the logical thing to do next is mount the fan controller half way in between. 

I removed the coolant reservoir to give me a little working room. This corner directly behind the right headlight was the best location for the controller I used. The plan was to keep it accessible but mount it solidly to the inner fender, and this worked out very well. The wire lengths were almost perfect and the controller was pretty well protected from a direct hit from the elements. 

There was plenty of room to get a drill in there and drill a couple of small holes to mount the unit with two sheet metal screws. I made a template of the bolt pattern from the controller to a piece of paper, and then marked where I wanted the holes in the inner fender with a sharpie.

Note the light blue square with the white dot in the center located on the upper right hand corner of the controller ...that's the adjustment switch, or rheostat, to let you set the temperature at which the fan will come on.

It will require you to use a very small flat head screwdriver to adjust, (a Craftsman pocket screw driver was perfect), and there is enough room to get to it even with the coolant tank back in its place, and the engine running at full operating temperature. No problem. Later, during the first warm up test, I just watched my truck's temperature gauge to set it where I wanted, and then fine tuned after the fan cycled a couple of times.

Also, note the ORANGE wire coming out of the upper left hand corner of the unit that has an ATC fuse holder in it. That's where I decided to use a 25 Amp circuit breaker going to the fan instead of a fuse. That's what the fan manufacturer recommends doing as they state the fan "can" draw upwards of 16 Amps or so upon start up ...but it falls back to around 7 Amps at full speed. I found my new fan would actually pop a 20 Amp fuse at first upon starting, but after a little bit of run in time it is drawing less current. It hasn't tripped the 25 Amp breaker, so the circuit can handle it with no concern now. I'll illustrate the MAIN system fuse in just a bit.











The fan controller is mounted and I'm starting to make run the wires through their conduits and secure them in place. There's the fan power and ground wires in one and the controller's temperature probe in the other. The other couple of wires take off toward the relay center.










And here's the pics of the belly of that relay box. I found by testing that the small ORANGE wire running to the blue Check Lamp Relay in the center has Ignition power on it only when the key is in the run position, and that's exactly what the new cooling fan controller needed to work as designed... only when the engine is running. 










Important note! If you are more comfortable stripping and soldering the last two connections than using quick connectors then it is advised to do so as the integrity of these connections are critical to prevent engine overheating or excessively high air conditioning refrigerant pressures. I can't over stress how important all the connections in this controller installation are!

I constantly watch the gauges closely during the operation of all my vehicles so I felt okay with doing the quick connectors. Done right they just don't fail any more often than any other connector on our vehicles. However, if you live in a salt air climate, or where salt is used on the roads during the Winter you need to go to extremes to complete the connections and insulate them from the elements.

So, here's that connection via Quick Splice Wire Tap - 18 to 22 ga. red for these smaller wires. The short section of YELLOW wire from the controller coming out of the conduit closest to you terminates in the Quick Tap and that Tap saddles over the ORANGE wire in the blue relay connector. Installed properly, it will not cut in half the wire to the relay, but just make a connection between the two wires. You can easily test your connection with an ohm meter or by checking for power on the end of the yellow with with the key on using your 12 volt meter or test light.

Remember that BLUE wire? It is the 2nd cooling fan power wire I mentioned earlier that won't be used due to the single fan installation here. We won't cut it off or disable it just because we may need it someday, but for now it does need to be tucked away in a safe manner inside the bottom of the relay box because it is hot when the fan is powered up.










So, that leaves us with the last connection to be made. The small (blurry) green wire coming from the controller has to go to, (if your truck has A/C), the Air Conditioning Compressor Clutch Relay.

On my truck it's the last single light blue relay mounted farthest from the battery, closest to the bulkhead, or firewall (as we use to call it). The A/C Relay has four wires coming up to the bottom. The one you need to tap into is RED with a BLACK tracer. It should be hot only when your A/C is turned on. That will insure that any time the air conditioning is running that the new cooling fan will be pulling air through the engine's radiator as well as the A/C condenser coil to keep the engine temperature and the A/C refrigerant pressures from going too high. 

The GREEN wire from the controller was the only one that I found to be too short to reach the bottom of the A/C relay harness, so I had to extend its length by splicing in an additional six or seven inches of lead prior to the last connection. Since the bottom cap of the main relay box already has lots of holes in it I chose to run the addition of GREEN wire straight through one hole and on toward the bottom of A/C relay splice connection (not pictured). 










And to complete these instructions, this is what I used for my battery connection (+) to the controller's red wire. The controller has a 40 Amp relay in it, but the fan manufacturer says to use a 25 Amp fuse to protect the whole new system.










I forgot to mention that you will have two BLACK ground wires to connect to the negative (-) side of the battery, one small Black wire from the controller, and a larger gauge that you have to add from the 
negative side of the fan connector. Be sure and test your fan ahead of the installation for proper polarity and direction, and mark the fan's connector accordingly. Very important!



See, that was easy!

-


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## TheRepairMan (Jun 30, 2009)

Post up if you have any questions, or if something was unclear. I'll be glad to help walk you through this project as much as I can. I was careful in the project not to do anything that couldn't be undone if need be in the future. I'll be reporting back here with updates as needed.

FYI... I bought the 16" fan off a machine shop that sells on Ebay, and the fan controller at an Advance Auto Parts store, but there are many sources for these parts as they are common to street rod builders and car customizers. Be sure to follow closely the instructions that come with your kits as they may differ from the information I provided on the ones I used.

This mod is through the test stages on my truck. I have about 4 hours of run time on it in lots of different conditions, including rain, and so far it's working perfectly for me. 

-R


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## TheRepairMan (Jun 30, 2009)

I forgot to show where the controller's temperature probe (bulb type) mounts. It needs to be placed in direct contact turned to run straight through the aluminum radiator fins as close to the upper radiator hose outlet as possible. Mine was just long enough and there is a gap at the upper right hand corner of the radiator between it and the shroud. The shroud, once bolted down, actually holds the new temperature probe gently in place.










Then, go over this electrical checklist from the controller.

(1) RED wire - fused, 25 Amp, to the Positive (+) terminal of the Battery.
(2) BLACK wire - to the Negative (-) terminal of the Battery. 
(3) YELLOW wire - signal wire from ignition source, to the small gauge ORANGE wire of the blue 
Check Lamp relay in main relay box, or any source that's hot with key turned to run only.
(4) ORANGE wire - to the (+) side of the cooling fan connector (switched power to fan). 
25 Amp Breaker or a 25 Amp Fuse is also suggested here by the fan manufacturer to protect 
the controller system in case the fan were to short circuit. 
(5) BLUE wire - not used, but can power up a second fan if needed.
(6) GREEN wire - signal wire from A/C power source, to the red and black wire in the single, light 
blue A/C relay's wiring harness, or hot only when the A/C compressor clutch is engaged. 

And the very last circuit wire...
NOT from the controller, Fan ground wire (-) (BLACK or any color wire), but a single solid 
ground wire added on from the Negative side of the Battery directly to the Negative terminal of 
the new Electric Cooling Fan Motor.

Reinstall the cooling system reservoir and the air filter plumbing, and let the test run begin!

-Roger


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## Grug (Aug 20, 2009)

Wowsers! Impressive, very impressive. This write up should go to the top of the site along with the timing chain write-up. You should be working for Haynes or Chiltons.

Sooo...will we be seeing a similar write up (with pictures) when you do your timing chain? 

Cheers!
Grug


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## TheRepairMan (Jun 30, 2009)

Grug said:


> Wowsers! Impressive, very impressive. This write up should go to the top of the site along with the timing chain write-up. You should be working for Haynes or Chiltons.
> 
> Sooo...will we be seeing a similar write up (with pictures) when you do your timing chain?
> 
> ...


Thanks, man! I wish I could take the time needed to do it right... get better organized with diagrams, and highlighted illustrations within the photos, plus it would help if the all posts here would remain editable for a longer period of time. I don't know if the mod is worthy of a sticky or not. That's not my call. 

And, yes, when I get time to break everything down to do the timing chain. I'll document the whole process in great detail. I'll probably generate and edit the write-up within a software program specifically designed for technical writing, and then insert a lot of photos and illustrations where called for so I'll have lots of time to proof read and make corrections prior to posting it here. That's my plan, anyway. 

So, here's my first real time road report on the truck's operation since the new electric fan mod...

My wife and I used the truck to go out to dinner, and to go get groceries last night. The first thing I notice is much less noise under the hood. That's because there's no mechanical fan spinning needlessly right from the start. The truck is noticeably MUCH quieter pulling out and accelerating, especially cold where the old fan clutch would still have been almost fully engaged. 

Now, my wife likes to run the A/C ALL THE TIME. She thinks she can't breath unless it's on ...even when it is cool outside ...she just doesn't like the humidity, so naturally, when the truck's A/C is on now, by design so is the cooling fan, just like all modern vehicles. That meant, because it was pretty cool last night the engine temperature never even made it to half way where the fan would normally kick on. The ONLY drawback to all that is that it's not going to get better fuel mileage with both the A/C and the new Electric Fan running. 

Those devices both consume electrical and mechanical energy in order to exchange heat to cooling, but even at that I'll have to say they worked very well, and the electric fan operating noise was completely undetectable when running unless we were at a stop, and even then I had to strain to hear it at all. 

Most importantly, the alternator and battery were able to keep up with the extra voltage and current required, even with the headlights on. My volt meter never dropped below 13.3 charging volts at any time during my 6 hours of running so far. All's well at this point! Note, my battery and alternator are both about three years old with only about 15,000 miles on them so I didn't expect they wouldn't work well with this mod. I'm working on replacing as many interior and exterior incandescent light bulbs on the truck as possible with LEDs to make it consume even less electrical power. That makes for less load which equates to more fuel efficiency, and yes, even those small amounts count. 

One other thing highly worth mentioning, if I haven't already ...with a total lack of mechanical fan noise, you can hear any, and all, engine internal noises. I'm hearing clearly, things there now I've never heard before, but that's a good thing actually, so I can stay abreast of any pending problems within the motor itself, and including all the belt driven accessories.

So far, I really like the fan mod overall, and the slight drawbacks are over weighed by the advantages. As long as it proves to be highly reliable, I won't be switching back any time soon. 

-R


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## TheRepairMan (Jun 30, 2009)

Here are some links to the parts I used. I am in no way connected to or responsible for, the vending of these or any parts listed on this web site. I can't profit from the sale of these in any way. I simply found through my own research and testing that they were good values and that they works best for me and my application. Take a look if you are interested, and study all your options before making a decision for yourself. 


I was unable to find a fan this size at this good of a price anywhere else. This seller has a real brick and mortar automotive machine shop and has been in operation in Kingsport, TN for over 15 years. Skip White Performace-Home of Racing Performance

The 16", 12 volt, reversible, push/pull cooling fan...

Super 16" Reversible Electric Fan 200 Watt HC 7105 | eBay











The Adjustable Electric Fan Controllers are available through just about any automotive parts supplier. Just make sure you get one with the temperature probe that slips in between the radiator fins instead of one that has to screw into the water jacket or threaded port somewhere on the engine.

The Adjustable Cooling Fan Controller with Relay...

Buy Imperial Adjustable Thermostatic Fan Control 226204 at Advance Auto Parts










All other hardware, electrical connectors, conduit, nuts and bolts, etc., were easily obtainable at my local hardware and automotive stores. I guess I had another $15 to $20 in that stuff, so a total right at $100 for the whole project.

-R


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## Erics_Daily (Feb 18, 2006)

> The Adjustable Electric Fan Controllers are available through just about any automotive parts supplier. *Just make sure you get one with the temperature probe that slips in between the radiator fins instead of one that has to screw into the water jacket or threaded port somewhere on the engine.*


Why is this?


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## TheRepairMan (Jun 30, 2009)

Erics_Daily said:


> Why is this?


Whether to use a temperature probe (bulb) type, or one that you have to thread in somewhere? Well, it's your choice, but just from my own experience the probe is much faster, easier, and works very well. Why would you want to mess with extra plumbing if you don't have to? Trying to find or make a hole, thread it to some odd size, chase down adapters, and then hope nothing goes wrong with your new kit, or the plumbing. Not me, if there's a choice ...plus, I prefer to be able to reverse or uninstall any kind of mod I do.

I guess you could say I'm more of an electrician than a plumber.

-R


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## SPEEDO (Jun 9, 2003)

^ I am with you, I like to un-do things if I have to....


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## TheRepairMan (Jun 30, 2009)

Short term update: It's been a couple of weeks, and this was the coldest day I have run it so far. One of those mornings you really need some heat and defrost, and I'll have to say it all performed just as planned. I couldn't be happier... well I could ...if it would get about 50mpg, but I think we all know that ain't going to happen. It did seem to warm up quicker, and my drive to work this morning was plenty warm inside the truck, 27* outside, and the cooling fan never had to run even once, and that was even sitting through a few red lights.

Coming back home the long way including stops, ambient temps were around 50* and the fan cycled two times during 1-1/2 hour drive in traffic. The new fan cools it quickly, and only ran for about 1 minute each time. Battery voltage never changed, although we know it consumes a few amps, the charging system was easily able to keep up. 

The truck warms up slightly faster, has slightly less load on the engine almost always, and cools down faster and better than it did with the mechanical fan and clutch. 

Though testing has been short, this appears to be a very good mod, so maybe we do need to request it be made a "sticky" here. 

-Roger


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## SPEEDO (Jun 9, 2003)

Thanks for the up-date, how hot are your summer temps? My area gets to 110-115+ (it hit 123 one summer) think that set-up could keep up?


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## TheRepairMan (Jun 30, 2009)

SPEEDO said:


> Thanks for the up-date, how hot are your summer temps? My area gets to 110-115+ (it hit 123 one summer) think that set-up could keep up?


Yeah, it's only passed the mild weather tests so far.

It doesn't get nearly that hot here where I live. It might top out 95* to 100* once in a while, but I can see no reason this system should not be able to keep up and cool the engine very well in average climates. That said, under the most harsh of conditions, it will work the alternator and battery just a little bit harder. That means they might run hotter than normal, so in those extreme high temps, if your mechanical fan is keeping it all cool then you may be better off keeping it in operation.

I don't know if going with an aftermarket electric cooling system like this is more reliable than mechanical in the long run or not. It has to be a little more efficient in average weather. I am thinking about running a second, but smaller, pusher fan in front of the radiator and condenser just as back-up cooling, but not sure about that yet. There's not much room up there and it would have to be on its own dedicated circuit to be a redundant system to protect the engine. Just thinking... 8"... 10"... I'm not sure.

Either way, I'm sure going to put it all to the test next year, with high hopes that it gives me no problems. This forum will be the first place I let know if any of it fails. I don't have any reason to believe it will from what I've seen so far. Eventually, everything electrical and mechanical fails, but the unknown is how long any system will last. 

-R


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## SPEEDO (Jun 9, 2003)

with the (stock) mechanical set-up, my temp gauge will go up half way and stay there, no matter if I am towing jet skis to the lake with the ac on or just driving around town... I was just thinking I might be able to gain a hp or two and maybe a mpg or two...


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## TheRepairMan (Jun 30, 2009)

SPEEDO said:


> with the (stock) mechanical set-up, my temp gauge will go up half way and stay there, no matter if I am towing jet skis to the lake with the ac on or just driving around town... I was just thinking I might be able to gain a hp or two and maybe a mpg or two...


We are thinking alike about the power and fuel efficiency gains, but I think expecting one or two hp, as well as mpg would be maybe too optimistic right now. I'm hopeful there will be some gains, but I'm just not sure yet. Mine won't be going on a dyno to measure total output any time soon, but I will watch the fuel mileage in the coming months.

I know the engine is much quieter, and doesn't sound like an airplane taking off when pulling out now. Just knowing it's not wasting fuel spinning that fan up all the time makes it worth while to me. How it will handle the heat where you live, or if it's worth while for everybody... I honestly can't say.

-Roger


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## SPEEDO (Jun 9, 2003)

I suppose I could find a math wizzard (probably a little kid) to figure out how much air the mechanical fan is moving, then find a fan set up to match or surpass it... that stock fan does make a lot of noise, I may not have the room that you did, my fan clutch is part of the w/pump (Z24I) I probably would have to make some mounting brkts for the fan, I dont like the zip ties thru the rad set-up


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## TheRepairMan (Jun 30, 2009)

SPEEDO said:


> I suppose I could find a math wizzard (probably a little kid) to figure out how much air the mechanical fan is moving, then find a fan set up to match or surpass it... that stock fan does make a lot of noise, I may not have the room that you did, my fan clutch is part of the w/pump (Z24I) I probably would have to make some mounting brkts for the fan, I dont like the zip ties thru the rad set-up


Yeah, I'm not a big fan of attaching anything directly to the radiator core either. Maybe it can be safely done on a new radiator, but to do that to our older cores would be risky, IMO.

Now, I'm no engineer, and I'm old, but calculating air flow with the stock fan seems a bit challenging to me. There are a few constant factors, but given that the mechanical fan has a viscous clutch, and is constantly variable depending upon temperatures and engine speed, it gets a bit complicated. I'm sure it could be done ...somebody had to calculate it prior to manufacturing ...probably some kid! 

The electric fan, on the other hand, the air flow can be calculated fairly accurately due to all the constants. Its speed may vary just small amounts due to slight voltage changes between idle charging, and above idle regulated voltage. 

It would take just a little work, but obviously you would need to take precise measurements between your radiator core and the waterpump hub, and proceed based on that. Usually they post up the new fan's dimensions and specifications on their web page. If not, I can get those for you.

-R


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## jp2code (Jun 2, 2011)

I haven't visited this forum in a long time.

Hey everyone! I noticed this past weekend that the stock fan on my 1994 is starting to crack. The cheapest replacement I've been able to find is about $30 + $15 shipping. Next, everyone I talk to says to replace the fan clutch while I'm doing this, and they seem to be about $65 + shipping. So, let's just say $120, if I'm doing the work.

Now consider this item on eBay: 09 11 Nissan Maxima Radiator AC Dual Cooling Fan Assembly 214819N00A New | eBay for $140, shipped (for posterity, if the link dies, just search eBay for part #NI3115139).










This is a Dual Fan made by Nissan for the 2009-2012 Nissan Maxima with the 3.5 Liter V6 and every Maxima probably comes stock with A/C and an Automatic transmission. My truck does not have A/C (sniff) and I'm zipping through the gears with a 5-speed Manual Transmission. In other words, if this fan can cool the Maxima, it should handle my workload with no problems.

One of the things I like about this fan that I want to incorporate is this nice little plug in:










I'd like to plug a harness section into that, over into where the Temperature Sensor is on my D21, and into my truck's power supply (i.e. the battery).

I am currently waiting to hear back from someone what the dimensions of this fan are. As long as it is not too wide or too tall, I'm going to snag it for my application.

My existing stock fan is cracked - not broken. Therefore, I am not forced to rush into this. I have the luxury of taking my time and doing it correctly.

If anyone knows of any issues, kindly speak up before I jump.


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## TheRepairMan (Jun 30, 2009)

I found that mine was cracking also, when I removed it. I'm not sure if they eventually hand grenade or not, but yeah, I don't see why those fans wouldn't work just fine on your truck. I'll bet it's been done before. 

That stock temperature sensor isn't designed to run fans through. They draw too much current for one thing. Don't do that ! Do take your time to do this right! Any electric fan, or fans need to be run on a 20 Amp fused circuit, through a fairly heavy 30 to 40 Amp relay, and then you are still going to need to add a controller. I'm just not sure of using the stock sensor, or switch you are talking about. That doesn't sound right to me right now.

They do make one even simpler to wire up than the one I used. And, actually you "can" run your fan power straight from the battery, on a fused wire, and the ground circuit through the thermostat below. It's got some pretty heavy contacts in it. I've done that on other vehicles, and it works fine, and is still adjustable.








Or this...
http://www.jegs.com/i/JEGS-Performance-Products/555/52125/10002/-1









It doesn't really say what Amp rating these controllers will carry. I'll recommend controlling a fan relay in line to ease the load and make the controller last.

-R


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## jp2code (Jun 2, 2011)

Actually, I was thinking about this part of the D21 Service Manual:









My guess is the connector that goes to the Maxima's electric fan takes 
 Power,
 Ground,
 Temperature Signal, and
 A/C On/Off signal (maybe)
If so, #1 and #2 are simple, #4 could likely be eliminated. So, that just leaves item #3.

Anyone know what section of the *2009 Maxima Service Manual* would have similar coolant temperature sensor information? I'd like to know what temperatures its sensors are looking for. I might be able to add resistance to my connection to match the Maxima fan's requirements.


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## jp2code (Jun 2, 2011)

OK, I found this in the 2009 Maxima Service Manual, in the EC section:










Hmmmm... I'm wondering how I can tell the fan to turn ON and OFF with this Engine Speed, Refrigerant Pressure, and A/C operation inputs...

Gotta think about this one.


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## TheRepairMan (Jun 30, 2009)

Let us know how that turns out, jp2code. In my humble opinion you are attempting to do more than necessary to make this happen... too complicated, not to mention starting at spending $140 for the dual fan assy. The second problem I see is those fans would eliminate using the stock fan shroud. Not a good idea.

Never the less, it is an option for those with whom money is no object, and who wish to keep some type of OEM Nissan fans employed.
-R


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## jp2code (Jun 2, 2011)

I appreciate your opinions, R. I haven't purchased the Maxima fan, so my options are still very fluid.

Case in Point: I've recently discovered the early Nissan Frontier trucks had an electric fan option. A Nissan Frontier electric fan is much less (LINK) than that Maxima version, would be more likely to bolt in with no modifications, and the connectors might even match up to the Hardbody's electronics.










I like that idea a lot more.

The fan by Skip White certainly looks capable (awesome website, too), and is likely more than a Hardbody would ever need; however, I have had bad luck in the past with those "sandwiched in" temperature sensors. I would rather find some way to tap into wiring and sensors that already exist on the truck instead of trusting my luck that my modifications would remain in place for 100k miles.


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## TheRepairMan (Jun 30, 2009)

Yeah, that fan might work just as well. I'm not sure there is any way to use the existing D21 systems to trigger an electric fan, though. The temperature sensors on our trucks for the gauge and for the fuel system are "variable resistance sensors" just as your first diagram suggests, that don't have a set of contacts that ever close, as a temperature "switch" would.

There would have to be a dedicated "temperature switch" for the cooling system that would close at a certain temperature to ground the solenoid side of a fan relay, and go open as the engine cooled down. That's the old way cars do it, but now days all is sensed and switched through the Engine Control Units and they don't need an on/off temp switch. Our trucks just don't have that capability, not that I'm aware of. So basically we are talking about the difference between a sensor and a switch. They can look identical, but work VERY differently.

I think you are doing the right thing by researching this whole thing out thoroughly before you commit. I'll try to assist any way I can.
-R


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## TheRepairMan (Jun 30, 2009)

Well, I said I'd report back here if any kind of a problem came up, so...

This whole thing has worked perfectly until lately during one of our coldest mornings of the Winter season. I noticed immediately upon start up one morning that the electric fan was running. Odd! I know that's not right... there's no A/C on, and no reason for it to be running on a dead cold, 17*F engine. That completely defeats the goal towards its best engine efficiency. 

So, I have driven it to work a few times just to monitor what's going on. Seems that as the truck and everything under the hood finally warms up that the controller reverts back to working normally, at least it did for a few days, but now it has the fan going all the time, non stop. That won't do at all. Some cool days I've just pulled the fuse and run it with no fan, all the time closely watching the temperature gauge. Luckily, I haven't had to stop and put the fuse back in. The engine stays in the normal range with the gauge only going even near half way when at long stop lights.

Long story short. I got a hold of a defective controller. After researching some reviews, it looks like I'm not the only one. This "Imperial" brand sold at Advance Auto Parts has a history of failing, so I'll be replacing mine with a newer design from Derale. I have used theirs before with no problems at all.

I'll keep updating this thread as I get this done. It sucks, but parts do fail sometimes. Maybe more often these days than they should. Probably because "we" try to spend as little as we can on parts. The cheapest often isn't the best route to go, as this has proven.

Stay tuned!

-R


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## TheRepairMan (Jun 30, 2009)

Advance Auto Parts agreed to warranty the Imperial controller for me, so I swapped it out yesterday. I'll admit that that was a pain... more or less, inconvenience to have to change it out, but it just meant taking the old one off and laying the new one beside it to cut all the wires to the same lengths, and crimp new connectors on in a couple of places. Not hard, just time consuming. 

But, anyway, the replacement Imperial brand controller works just fine for now, and if this one should fail I'll go back to plan B and install another brand. Overall, I'm still glad I made the full fan swap. The weather here is slowly warming up now, so I'll do a hot day report soon.

-Roger


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## TheRepairMan (Jun 30, 2009)

Just a quick update. The cooling fan and controller were put to the test pretty well today. Ambient temps out got up to 82* and I was in traffic stop and go for about twenty minutes and another twenty on the road. It's not really hot outside yet, so I'll be watching it and reporting what I see.

All's well so far... the engine is keeping its cool nicely. The temp gauge is staying below the half way point even with the AC on some.

-Roger


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## cbrer (Apr 22, 2013)

*Electric fan mod.*

Outstanding project, and a quality install. I plan on performing this mod. to my 1995 hardbody with the 3.0 V6. Would you happen to know if the pulley clearance is the same for both models? 

:newbie: Thanks! Brian


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## TheRepairMan (Jun 30, 2009)

cbrer said:


> Outstanding project, and a quality install. I plan on performing this mod. to my 1995 hardbody with the 3.0 V6. Would you happen to know if the pulley clearance is the same for both models?
> 
> :newbie: Thanks! Brian


No, Brian, I don't know. I didn't even know what it was going to end up on my 4cyl until I did some trial and error mock up. I always had the last option of mounting the fan directly to the radiator cores, but that is a little risky with the vibration and stress added to an old radiator. I didn't want to take that chance, so I made the shroud mount work with just a little room to spare. 

You can do some pretty close measurements between your radiator and the mechanical fan hub, and compare that to the overall height of the cooling fan you are going to use, then calculate just enough room attach the fan to your shroud and come up with shims or washers under the bolts to move the fan closer or further away from your radiator. Mine's pretty darn close, but doesn't touch when running, and that's what counts.

I've seen several street rods running these fans and they have almost no room left at all between the fan and the other components. I guess you do whatever it takes to make it work. Some run pusher fans, but there isn't any room for that on our trucks unless you don't have A/C. You might get two 6" or 8" fans up front, but I'm not sure they would move enough air.

-R


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## TheRepairMan (Jun 30, 2009)

81* here today in stop and go traffic for about 30 minutes, and at a bunch of red lights, it all cooled very well. I even ran the AC some and as the compressor cycled on and off normally, so did the new fan. Engine temps never got quite up to the halfway point on the gauge so it's doing exactly what it's suppose to do so far. It's not really HOT out yet, so more testing to come.

Keep in mind, I never had any cooling problems with this truck. The idea behind the electric fan was to reduce the dynamic load or drag from the old mechanical fan. Turned out my old fan was getting lots of cracks in it anyway and was in danger of coming apart. 

I'm trying to schedule a time to take the truck out of service long enough to do the timing chain and rails. Maybe the first week of July.

-Roger


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## jp2code (Jun 2, 2011)

How did your summer go? Did the fan survive?


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## TheRepairMan (Jun 30, 2009)

jp2code said:


> How did your summer go? Did the fan survive?


Oh yeah... it went very well. I didn't put a ton of miles on the truck last year. Probably just over 5,000, but the fan, controller, and installation gave me no problems at all in 2013. Even on the very hottest days we had (mid 90's), in traffic, with the AC on, the gauge never climbed over the half way mark. Most days, the fan hardly ever cycled at all, and the gauge would run at about one third. That seems to be normal on my truck with the factory thermostat in it. 

I couldn't answer my own question as to whether it gave me any better return in fuel mileage, but I don't see how it could not help since it's no longer spinning a mechanical fan at any time. I absolutely would do this modification again if I had it to do over, but still I caution that this wasn't done to correct any sort of overheating situation. It isn't designed to make the engine run cooler than stock, just more efficiently... less constant mechanical load. When the fan does come on it draws a load on the battery and alternator, so is it a wash energy wise? I don't know, but I feel real good about the overall system operation.

So, after the initial glitch with my first controller being defective, once I replaced it in 2012 the new system has worked just as well as I hoped it would.

-Roger


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## jp2code (Jun 2, 2011)

That sounds awesome.

I picked up a dual fan from an old Altima that I was going to wire up, but the temperature started rising really fast in the spring before I got it on.

Hearing your success really makes me want to try it again while the weather is still cool enough.

At one point in the summer, I found myself pulling much more of a load than even the Heavy Duty D21 should be doing.

It was around that 100°F mark, and the water temperature got close to the HOT mark even with the fan clutch. I was really worried, and I remember thinking I was glad I didn't have to worry about the electric fan that day.

Poor little truck!


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## Realred96 (Aug 1, 2013)

Going to do this soon. Went to the local pick a part to do field research and I agree with Joe that the Maxima fan set up is the way to go. The fans and motors seem to be more "higher grade" than the Altima units. May just be my imagination.

Another issue I see is that you need to be able to have logic that cycles the fans when the A/C compressor is on. It is in the Maxima ECU logic but sadly lacking in the D21 or WD21 ECU. his logic will have to be a separate circuit than the engine coolant temp switch, and will have to play nice together.

This could get complicated but I am in no hurry so I welcome the challenge.

I hope I am not over thinking this.

Jim From Houston


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## TheRepairMan (Jun 30, 2009)

Realred96 said:


> Going to do this soon. Went to the local pick a part to do field research and I agree with Joe that the Maxima fan set up is the way to go. The fans and motors seem to be more "higher grade" than the Altima units. May just be my imagination.
> 
> Another issue I see is that you need to be able to have logic that cycles the fans when the A/C compressor is on. It is in the Maxima ECU logic but sadly lacking in the D21 or WD21 ECU. his logic will have to be a separate circuit than the engine coolant temp switch, and will have to play nice together.
> 
> ...


Hey Jim,
I'm real happy with the fan control relay I used. Mainly because it's self contained with its own replaceable relay, plus a sealed temperature probe, automatic, fully adjustable, commonly obtainable at most parts stores, relatively inexpensive, and had very clear connection instructions. This is about the fifth vehicle I've used this type on, and they do a great job, IMO. Here's the third post in this thread. 

http://www.nissanforums.com/hb-truck/172728-electric-cooling-fan-controller-done.html#post1360511

Take a closer look at how this wires up before you jump in with involving the ECU and engine temperature circuit.

*(1) RED wire - fused, 25 Amp, to the Positive (+) terminal of the Battery.
(2) BLACK wire - to the Negative (-) terminal of the Battery. 
(3) YELLOW wire - signal wire from ignition source, to the small gauge ORANGE wire of the blue 
Check Lamp relay in main relay box, or any source that's hot with key turned to run only.
(4) ORANGE wire - to the (+) side of the cooling fan connector (switched power to fan). 
25 Amp Breaker or a 25 Amp Fuse is also suggested here by the fan manufacturer to protect 
the controller system in case the fan were to short circuit. 
(5) BLUE wire - not used, but can power up a second fan if needed.
(6) GREEN wire - signal wire from A/C power source, to the red and black wire in the single, light 
blue A/C relay's wiring harness, or hot only when the A/C compressor clutch is engaged. *

Keep us posted!

-Roger


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## Realred96 (Aug 1, 2013)

You have the better solution. I did not catch the part about the A/C relay circuit (6) on that controller. 

No brainer to use that controller, especially since you have already proven it out.

Will definitely keep posting status as it happens.

Jim


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## TheRepairMan (Jun 30, 2009)

Realred96 said:


> You have the better solution. I did not catch the part about the A/C relay circuit (6) on that controller.
> 
> No brainer to use that controller, especially since you have already proven it out.
> 
> ...


That said, I did have one develop a problem. As I recall, after about a month it started running the fan shortly after start up on a cold engine. At least it didn't fail the other way and not turn the fan on at all. The store exchanged it with another, and I haven't had any more trouble. The system was a real trooper all through last summer, and unless I sit and idle a long time somewhere it hardly ever has to run the fan during the cooler seasons.

It's always an option to run a manually operated toggle switch as a backup just in case the controller were to malfunction, but that kind of defeats the whole idea of an "automatic" temperature fan control. 

I also see that the original link to the fan controller I used is no longer working. I find one and fix that link.

Once again, here's the controller I used... http://derale.com/products/electric...fan-clutch2013-10-18-11-52-51928758585-detail

And the installation instructions per Derale... http://derale.com/images/stories/virtuemart/product/pdfs/16759.pdf



-Roger


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## CMax03 (Jan 17, 2009)

I know it's 2 yrs old! You fell any extra Horsepower since the mechanical fan in't always on?


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## TheRepairMan (Jun 30, 2009)

CMax03 said:


> I know it's 2 yrs old! You felt any extra Horsepower since the mechanical fan in't always on?


Well, that's a no, because my driving style doesn't call for more horsepower. As a matter of fact I haven't ever pushed the throttle to the floor, and I hardly ever even turn over 3,000 rpms. I did the mod purely for better fuel economy, and it certainly hasn't hurt it any.

-R


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## rogoman (Dec 16, 2004)

An excellent write-up. Glad to hear that everything is working good.


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## TheRepairMan (Jun 30, 2009)

rogoman said:


> An excellent write-up. Glad to hear that everything is working good.


Yes sir, thanks! So far so good. We all want our trucks to be as reliable as they can be, just to prevent the inconvenience and expense of being stranded somewhere, so I've been aware of the temperature gauge at all times, and it has yet to go beyond the halfway point under even the most harsh conditions. The largest load I've hauled on a hot day was just under 800 lbs, over a pretty hilly 30 mile route with some stop and go driving, and the engine kept its cool. 

I can hear the fan run when it does come on, which is a good thing, so I glance at the volt meter to make sure the alternator keeps up, and listen for the fan to cut off again in a minute or so. When I'm running the AC the fan stays on as long as the compressor clutch is engaged, so sometimes the engine temperature will actually start going down to around the first third of the reading. In other words, the engine shows it's running cooler than it has to during AC operation. That's also a good thing. The AC doesn't stress as much. 

We did one of these electric fan and controller kits on a heavily modded 56 Chevy at work recently. It was converted to a late model Chevy Corvette crate motor (very expensive custom project) so it got a lot higher dollar fan, and controller, for the best protection, but it works exactly the same way mine does and runs it all just cool enough for short hard runs or long slow parades.

-R

Fall 2014 Update:
We didn't have the hottest weather on record here, but even on the hottest days in the 90's in traffic the truck kept its cool. The temperature gauge may get up to the half way mark, but no higher. I also pretty much took everything back apart this summer just to make room for doing a timing chain service along with a new waterpump and radiator. All was well, and I didn't have to make any adjustments or corrections to the electric cooling fan system installation. BTW, the radiator had failed due to the plastic neck deteriorating at the upper hose... not uncommon for radiators to fail this way being over two decades old, and nothing at all to do with the fan and shroud mounting.

-R


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## CMax03 (Jan 17, 2009)

Yeah I've thought about doing the same for years just to free up about 15 hp at cruising speeds since there's enough air moving thru the radiator that the fans aren't even needed...I'm a Permacool customer and they offer sevral adjustable controller kits as well the best one I believe is the one with the short pipe tht you cut your hose and insert this pipe section that has a welded in temp sensor bung and the rest is simple wiring.... I'm at about 365,500 miles and I'm seriuosly thinking about pulling the engine to have the cylinders bored out .5mm and install overbored pistons cause I'm burning oil really bad....at once I take it down to do this the electric fan mod will happen...Nice write up TRM!


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## TheRepairMan (Jun 30, 2009)

Thanks, CMax03 ! Keep us posted with progress on your rebuild.

-R


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## TheRepairMan (Jun 30, 2009)

Update: 

My electric cooling fan is still working just fine, but for the third time I'm having to replace the electronic thermostatic controller. I went with a different type altogether this time, but had to add yet one more relay to turn the fan on with the AC. It's gotten a little complicated now as far as the wiring goes, but I was still able to keep it working as designed.

I'll be glad to answer any questions.

-Roger


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