# 91 Sentra Cluster Swap



## heaton84 (Jan 18, 2006)

Hi all, I am trying to swap the instrument cluster in a 91 Sentra with that of an 86 Sentra (going to gain a tach in the process). I have a question on wiring, hopefully someone can help me. I was able to track down what most of the connections were, as Nissan gracefully labelled the traces on the back of the cluster...

There are, however, two traces that go to the speedometer that I cannot figure out. They are both labeled with identical Japanese characters (I never did learn Japanese), but using a multimeter I determined that one is basically ground and the other is +5VDC.

Now I really don't want to fry the speedometer on this guy, so I was wondering if anyone could provide some insight on the wiring diagram, or even simply if reversing these two could spell death for the speedometer. Thanks.


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## jakehale (Aug 8, 2004)

heaton84 said:


> Hi all, I am trying to swap the instrument cluster in a 91 Sentra with that of an 86 Sentra (going to gain a tach in the process). I have a question on wiring, hopefully someone can help me. I was able to track down what most of the connections were, as Nissan gracefully labelled the traces on the back of the cluster...
> 
> There are, however, two traces that go to the speedometer that I cannot figure out. They are both labeled with identical Japanese characters (I never did learn Japanese), but using a multimeter I determined that one is basically ground and the other is +5VDC.
> 
> Now I really don't want to fry the speedometer on this guy, so I was wondering if anyone could provide some insight on the wiring diagram, or even simply if reversing these two could spell death for the speedometer. Thanks.


Ignition positive and 
Ignition Negative...

basically Japaneez character (-) (+) the character is ignition

Hope that helps ya for that


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## heaton84 (Jan 18, 2006)

As I said both tracks are marked identically so I can't discern which is which.


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## heaton84 (Jan 18, 2006)

Well, I ended up pulling the cluster apart (always wondered what that stuff looked like on the inside), and traced the leads to a pair of black and white wires. I assumed that black was negative, so white had to be positive... and it's working just fine right now.

Now to just find the wire on the ECU for the tach...


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## jakehale (Aug 8, 2004)

Oh sorry. wish I could have been more help

Let us know how it works out


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## heaton84 (Jan 18, 2006)

Well, after much fussing around with the wiring (ended up tapping into origional harnesses and using two 9-pin connectors from radioshack due to wire length issues), I got the cluster in. Everything works... except for the tach. I tried tapping into the blue wire with a black stripe and got nothing... so I tried the blue wire with the white dots and also got nothing... maybe these aren't the right wires for the tach but that's what I am led to believe are the right ones...

Maybe it's just a bad connection somewhere behind the cluster (I hope)...


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## heaton84 (Jan 18, 2006)

heaton84 said:


> Everything works... except for the tach. I tried tapping into the blue wire with a black stripe and got nothing... so I tried the blue wire with the white dots and also got nothing... maybe these aren't the right wires for the tach but that's what I am led to believe are the right ones...
> 
> Maybe it's just a bad connection somewhere behind the cluster (I hope)...


Looks like I may have a dead tach  I've triple checked the power connections and they are fine. The tach sensor wire from the cluster to the ECU is fine, but I get no movement on the needle no matter what speed the engine is turning at.

Guess I'll try the 2.2Kohm resistor streight to the negative side of the coil... (that's how it's done for OEM, right?) Or does anybody have a better way to test it?


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## jakehale (Aug 8, 2004)

heaton84 said:


> Looks like I may have a dead tach  I've triple checked the power connections and they are fine. The tach sensor wire from the cluster to the ECU is fine, but I get no movement on the needle no matter what speed the engine is turning at.
> 
> Guess I'll try the 2.2Kohm resistor streight to the negative side of the coil... (that's how it's done for OEM, right?) Or does anybody have a better way to test it?


Did you follow the directions that Toolapcfan had laid out?


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## heaton84 (Jan 18, 2006)

jakehale said:


> Did you follow the directions that Toolapcfan had laid out?


If you are refering to http://nissanforums.com/showpost.php?p=551545&postcount=10, then yes. I have no way of testing, so either it's the ECU or the tach. I'm hoping it's the tach...


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## jakehale (Aug 8, 2004)

heaton84 said:


> If you are refering to http://nissanforums.com/showpost.php?p=551545&postcount=10, then yes. I have no way of testing, so either it's the ECU or the tach. I'm hoping it's the tach...


Well I was thinking more along the lines of this link,

Nissan Cluster


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## heaton84 (Jan 18, 2006)

jakehale said:


> Well I was thinking more along the lines of this link,
> 
> Nissan Cluster


I guess I followed it as much as I could have... I ended up using wire taps and 2 9-pin connectors from radioshack to connect the new cluster in (couldn't figure out how to release the pins based on his description, plus this left me a quick way out if I needed to go back to the old cluster). Everything on the cluster does work... except for the tach. Since that pulls it's power and ground from other instruments that seem to be working, I can only speculate that it's not getting a signal (or it's dead).

If it helps any, this is the new tach I swapped into my '91 senta: http://cgi.ebay.com/ebaymotors/86-S...33675QQitemZ8029394412QQrdZ1QQsspagenameZWDVW
Couldn't find the part # on it anywhere, and even if I knew where to find it now I hesitate to pull the cluster back out of the dash (my speedometer cable keeps breaking when I do that and I've had to krazy glue it back together twice now)


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## jakehale (Aug 8, 2004)

heaton84 said:


> I guess I followed it as much as I could have... I ended up using wire taps and 2 9-pin connectors from radioshack to connect the new cluster in (couldn't figure out how to release the pins based on his description, plus this left me a quick way out if I needed to go back to the old cluster). Everything on the cluster does work... except for the tach. Since that pulls it's power and ground from other instruments that seem to be working, I can only speculate that it's not getting a signal (or it's dead).
> 
> If it helps any, this is the new tach I swapped into my '91 senta: http://cgi.ebay.com/ebaymotors/86-S...33675QQitemZ8029394412QQrdZ1QQsspagenameZWDVW
> Couldn't find the part # on it anywhere, and even if I knew where to find it now I hesitate to pull the cluster back out of the dash (my speedometer cable keeps breaking when I do that and I've had to krazy glue it back together twice now)


Well, I'm thinking that I cant help you no more. Toolapcfan's write up was for an obviously different looking cluster, and year not to mention. And another not to mention, I havnt successfully done a swap yet. So I definataly dont want to give you bad advise.

Hope you get it working.


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## heaton84 (Jan 18, 2006)

The tach works. It wasn't the blue wire with the black stripe, but the red wire with the white stripe next to it that was the tach signal. However, I have no idea if this is the "oem friendly" tach signal coming from the ECU, or a direct connection to the coil. Does anyone know anything about this wire? Would putting a 2.2K resistor on the tach wire negatively affect things if this is in fact the oem friendly wire? The only thing that kinda bugs me is, according to this setup, my engine idles at 1,500 RPM (but will drop to 1,000 RPM). Is this typical of a 1.6L, or is something off?


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## heaton84 (Jan 18, 2006)

Well I think this wire is safe to use, however my tach is displaying roughly double what the RPMs should be (eg, it idles at about 1,400 RPMs... I found this engine idles at about 650... plus the needle moves far too much for just a little gas)

Anyone have any suggestions on how to halve the RPMs or reconfig the tach?


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