# Radiator fan not coming on



## Vantage (Nov 17, 2003)

Lets start by explaining that I understand how cars work and can do all the work, I just know nothing about this car.

1992 NX2000
SR20DE

The electric fan(s) are not tripping so the car overheats. I have solved the problem for now by wiring a switch where the relay was so when I am offhighway I can turn the fans on.

I would assume there is either a bad sensor or a broken wire but I have no idea where to start looking. I checked all over the radiator and there are no wires to there so I am stuck.

The engine is actually out of my car (and the radiator) right now as this winter it is getting "modifacations".


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## Slacky (May 31, 2004)

engine temp switch, kinda like a thermastat on the radiator tells the fan when to come on


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## lovemyser (Mar 14, 2003)

*


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## lovemyser (Mar 14, 2003)

I had huge problems with this, and never fixed it. I think it might be a computer failure of some part, but here's what I would try first, there is 2 sensors side by side on a coolant flow pipe right beside the #4 intake runner (near the power steering tank), one is a temp gauge sensor the other is your temp coolant sensor, you can either replace this sensor, or you can check the OHM on it, haynes will do a step by step check and replacement if you want to try that, you obviously are getting power because you have bypassed. Because your temp is controlled through your ECU it could very well be that the problem lays there, or as simple as what I just told you to do, or a relay replacement. One more thing is your temp gauge may be lying to you, unusual yes, but it could happen, my current stock gauge is 40-50 degrees off, you might want to invest in a aftermarket temp gauge before you start throwing a bunch of money at it.


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## Vantage (Nov 17, 2003)

Well its definatly overheating as I had steam twice before I bypassed the relay.

Slacky: There is definatly nothing in the radiator, I pulled the whole damn thing out and found nothing.

lovemyser: I remember pulling the connectors off a bunch of electrical stuff over there when I popped the motor out, I will take a peek in the morning when there is light.

On this topic does anyone know of any online manual or diagrams or ANYTHING on a NX2000 with a SR20DE? It's like the car that never exsisted =P


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## Slacky (May 31, 2004)

hmmmm idk dude


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## lovemyser (Mar 14, 2003)

Vantage said:


> Well its definatly overheating as I had steam twice before I bypassed the relay.
> 
> Slacky: There is definatly nothing in the radiator, I pulled the whole damn thing out and found nothing.
> 
> ...


More than likely there's nothing wrong with your radiator, I didn't know that you had had the motor out, I'm laying all my marbles on the Engine Coolant Temperature Sensor. I've taken mine out several times, its a tight fit, and you'll need a deep well socket, because of the connector being in the way(you'll know what I'm talking about) you can get away with using a standard I believe. 

Yes just get the sentra haynes manual for a 91-93 and it will have everything in there for your type car, its generalized, but if it was perfect you wouldn't need us 

Ohh by the way if you take that sensor out get another smash washer don't put any RTV or silicone on it, it throws off the readings.


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## Vantage (Nov 17, 2003)

Ok I will definatly look into that when I get up. Thanks for all the help.

I knew that Haynes had the Sentra manual and the stuff was close, but I was holding out until I knew that it was the best I could get.

You seem to have done most of the things I want to do, such as actually have enough room to fit my hand into the engine compartment by removing some of those damn hoses also know as "emission control". 

I have already ripped out most of my A/C stuff and I plan to use the A/C core as a second heater core. Sneaky sneaky (makes sense cause I live in Canada eh? That and I can cruise with the tops of more).

Like I said before I can do the work, I just need someone pointing me in the right direction.


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## toolapcfan (Jul 10, 2002)

http://www.nissanperformancemag.com/march04/fans/

Here's how I recommend you override your fans, should you decide you always want to be able to do that. Also check the diagram of the ECU to figure out which wire at the ECU triggers your fans to turn on. This wire will show continuity to ground when the fans are supposed to come on. If it does not, then the ECU is malfunctioning or not getting the signal it needs to know that the fans need to come on.


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## Vantage (Nov 17, 2003)

toolapcfan said:


> http://www.nissanperformancemag.com/march04/fans/
> 
> Here's how I recommend you override your fans, should you decide you always want to be able to do that. Also check the diagram of the ECU to figure out which wire at the ECU triggers your fans to turn on. This wire will show continuity to ground when the fans are supposed to come on. If it does not, then the ECU is malfunctioning or not getting the signal it needs to know that the fans need to come on.


Thats alot of work for something that I already did in 3 minutes. All I did was pull the relay for the fan out (yes the relay was good) and jammed a wire from the power to power.

This put the fans on constantly. By adding a switch and a longer wire I was able to run it under the dash so I could turn it on and off at my disgretion.

Thanks for the tip on the ECU, I will check that after I check the sensor.


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## toolapcfan (Jul 10, 2002)

Vantage said:


> Thats alot of work for something that I already did in 3 minutes. All I did was pull the relay for the fan out (yes the relay was good) and jammed a wire from the power to power.
> 
> This put the fans on constantly. By adding a switch and a longer wire I was able to run it under the dash so I could turn it on and off at my disgretion.
> 
> Thanks for the tip on the ECU, I will check that after I check the sensor.


No, it's not a lot of work and it's a hell of a lot safer than what you did, and the fans won't run when the car is off and run the battery down. Reminds me of people drilling holes in their firewalls to get a tach signal from their distributor when they can do it by tapping the same wire at their ECU. Not to mention you can run tons of wiring to the engine bay in 15 minutes without drilling any holes. But I digress, people just don't listen. There's the right way to do things and there's half assed ways to do things. The thing is, many times the right way is easier.


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## Vantage (Nov 17, 2003)

Valid point. I don't have to worry about it anymore as I am actually going to be fixing the problem. I have to rewire everything anyway as I am removing almost everything I can and putting in a different radiator and fans.


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## ºØmïñøü§ººÑéfåríøµ§º (Nov 14, 2006)

*ºØmïñøü§ººÑéfåríøµ§º*

In reference to your cooling fans not working.yOU NEED TO CHECK YOUR 'THERMOSWITCH' LOCATED AT THE END of your thermostat. 
the NISSAN ECL code is "0103" Coolant temperature sensor.

How to Read the Trouble Codes from the ECU

Locate the ECU (under your dash in the center) and look for a small screw next to a LED (towards the back end). 
Turn the ignition to the ON position (engine not running). 
Turn the screw fully clockwise, wait 2 seconds, and then turn it fully counter-clockwise. 
The LED will start to display the code by a series of long flashes, followed by a series of short flashes. Your check engine light on the instrument cluster will also flash in the same sequence. This sequence will repeat.



---a good location to see your engine codes: 
http://www.sr20forum.com/archive/index.php/t-96214.html

and 

- ATL-SR20 v1.0 -

---a good location to download your Factory Service Manual (your car is a B13):
PhatG20 - Downloads


In the service manual you will find the correct ohm load you should get when testing with a multi tester. I would post the OHM value, but i just ate and don't feel like getting up and flipping through it to find it. but i just looked at it an hour ago and know its there. I did give a link to download the manual so you can find it yourself, thats more than a catfish would do!


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