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Dead Fuel and temp gauges


AceJime
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Well from what i read in the frequently asked questions section I learned that my dead fuel and temp guages were almost definitely a result of a faulty voltage regulator. So i pulled out my dash cluster and had a look around. The voltage regulator (here forth referred to as VR) was pretty easy to spot, it's located in the top right corner when you turn the dash cluster around and are looking from the back. I gave it a quick test with my multimeter (black to negative of a new 9 volt battery, yellow to positive, blue to positive test lead of multimeter, and negative test lead to negative of battery) I found that the little bugger was only giving me about 3.5 volts, having followed the traces on the back of the cluster and finding out I need 8 volts going to the gauges, this VR is shot for sure. For reference the black wire is ground, blue is Vout (voltage out), and yellow is Vin (voltage in). With that I headed over to radioshack. As I'm perusing the component parts section I discover they only carry 5VDC VRs and 12VDC VRs. However given further investigation i notice they also have adjustable VRs. Great, so it's definitely do-able i'm just going to need a few extra parts. I end up getting the adjustable VR, a pack of 5 100 ohm 1/2 watt resisters (only need one), and a 1K ohm trimmer (basically an adjustable resistor up to 1k ohms), I also pick up a little 2"x2" PCB to put everything on. Now in order to get the VR to 8VDC I'm going to need to wire the 100 ohm from the adjust leg of the VR to the Vout leg, and the trimmer from the adjust leg to ground. The trimmer needs to be set at 540 ohms in order for the VR to put out 8 volts. Another important thing to note is that the trimmer has 3 legs, one of which is called the wiper (the back of the bag it came in will tell you which leg it is). The wiper needs to be shorted to one of the other two legs, it doesn't really matter which, and from then out it will act like a regular resistor except now it's adjustable. :tongue: I wired that all up on the PCB and connected it back to the cluster, being sure each wire went to it's appropriate place, and popped the whole thing back in the pathy. Grab my keys and turn her on, and all of a sudden my fuel gauge springs to life! Turns out I got a little over half a tank. :happy: As i let her run and warm up, my temp gauge slowly starts to rise as well! Cool all fixed, on to bigger and better things. Like figuring out why she idles so high and sporadically after she does get warmed up.

Edited by AceJime
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I'm no good with electronics, but this seems Pin worthy for those with aptitude. Hell, maybe someone will start a side business fixing these things.

 

Only side note: This is for the 86.5-93 gauge clusters as the 94-95 have a completely different set up??

 

I'm going to add a title description for clarity.

 

B

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If any one can please post the solution for fixing the Cluster voltage regulator link again, it would be greatly appreciated. I am not as technical as the man who was able to fix his on his own.

 

Thanks

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  • 2 weeks later...

The build that AceJime put up works. Just fixed my '91 pathy this way. As long as the water temp and fuel gauge fail simultaneously, you can be certain that it is the gauge cluster VR.

 

 

I made something similar a while back to adjust the voltage of my MAP sensor on my jeep, so the build was easy for me.

 

 

 

 

To fix this nuisance, it boils down to either:

 

1) Go to the junkyard and search tirelessly for another pathy to strip the gauge cluster for a possibly faulty regulator to install on your rig.

 

2) Dealer part purchase. Probably $20-30 for one. Just a guess.

 

OR

 

3) Buy the radio shack parts and make yourself a regulator for under 6 bux (if you have a soldering iron and enough common sense to unlock your door and let yourself inside at night, you can do this no problem.)

 

I used a generic adjustable VR (they're all the same), a 1k cermet potentiometer and a 100k Ohm resistor...like a $5 bag of goodies. Then you can PCB board it, or just solder the mess together and tuck it behind your cluster for hassle free operation. I'm not going to re-hash my build but i will have pics of the built VR assy soon, but for now here is a diagram to encourage those who might attempt to do this themselves.

 

 

 

 

I will add that this is a simple build. You only have to solder a few connections, and you're done. Or paypal me a few bucks and I'll start shipping these things out. =-]

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

KUDOS ACEJIME

post-29740-128157079994_thumb.jpg

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  • 5 months later...

The build that AceJime put up works. Just fixed my '91 pathy this way. As long as the water temp and fuel gauge fail simultaneously, you can be certain that it is the gauge cluster VR.

 

 

I made something similar a while back to adjust the voltage of my MAP sensor on my jeep, so the build was easy for me.

 

 

 

 

To fix this nuisance, it boils down to either:

 

1) Go to the junkyard and search tirelessly for another pathy to strip the gauge cluster for a possibly faulty regulator to install on your rig.

 

2) Dealer part purchase. Probably $20-30 for one. Just a guess.

 

OR

 

3) Buy the radio shack parts and make yourself a regulator for under 6 bux (if you have a soldering iron and enough common sense to unlock your door and let yourself inside at night, you can do this no problem.)

 

I used a generic adjustable VR (they're all the same), a 1k cermet potentiometer and a 100k Ohm resistor...like a $5 bag of goodies. Then you can PCB board it, or just solder the mess together and tuck it behind your cluster for hassle free operation. I'm not going to re-hash my build but i will have pics of the built VR assy soon, but for now here is a diagram to encourage those who might attempt to do this themselves.

 

 

 

 

I will add that this is a simple build. You only have to solder a few connections, and you're done. Or paypal me a few bucks and I'll start shipping these things out. =-]

 

 

KUDOS ACEJIME

 

Hello!

I'm new to the forum, got here looking for this information. And I have to say, after looking around a good bit, this forum has the best info on pathfinders I've found so far. I look forward to hanging out here!

 

Cheers!

~Dan W

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Hey, I've had this problem for about a year now and just came across this forum. I made my own according to the diagram and instructions, but I'm only getting 6.5 volts with a nine volt battery. Because the car is a 12 volt system would this be fine, or does anyone know what I might be doing wrong? Thanks

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  • 3 weeks later...
  • 1 month later...
  • 1 month later...

Still nothing.. I even tried 2 different VR's that were both good and still nothing is working.. Any help?

 

So you have the correct 8V output from the regulator? Can you check that you get 8V and ground at the gauges themselves?

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So you have the correct 8V output from the regulator? Can you check that you get 8V and ground at the gauges themselves?

 

Yes I Checked both and they were getting just over 8 volts. I will need to do that, the ground I know has problems. It burnt up one time a while back..

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Yes I Checked both and they were getting just over 8 volts. I will need to do that, the ground I know has problems. It burnt up one time a while back..

 

If you have an adjustable DC power supply (or can cobble some sort of ac/dc adapter together) then you might be able to try to power the gauge "manually" and see if you can get it to move. Of course the sender(s) could also be busted, it's just unlikely they that both died at the same time.

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Good idea, I was going to poke around the gas tank today and see where the wiring is all at. From what I understand, the wires are just a straight shot from the tank to the gauges so yeah. I also even switched the gauges themselves to see if that was the problem and still nothing.

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Good idea, I was going to poke around the gas tank today and see where the wiring is all at. From what I understand, the wires are just a straight shot from the tank to the gauges so yeah. I also even switched the gauges themselves to see if that was the problem and still nothing.

 

My guess is that the device in the fuel tank varies a resistance as the fuel level changes. This, combined with the 8V from the regulator moves the gauge a certain amount. But I could be wrong. Should be in the FSM...

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  • 9 months later...
  • 2 years later...

Thank You :aok:

 

I printed and created a new PDF (no way was I giving them CC info so I could download an original) and NPORA once again has this document on our own servers.

Pathfinder Common Problems/Fixes, Read this first! has had the first post updated with the local link to the file.

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Not all the gauge clusters (square) have a voltage regulator on the back, my 93 (hardbody) does not, I have pics of it also.

 

Not sure if the early clusters on the WD and D21 are the same as the one in my former 90 sentra, but the sentra came with one of 3 possible voltage regulators, one that looks like a normal transistor, one that is silver smooth case, and one that is black with heat sink fins on it, the silver and black one also have different length wires. I think it depended on whether the cluster had the tach or not.

 

When I inquired with my local dealer back home in NY the parts manager said she never saw the first type ( normal transistor type) I had to send her pics, I ended up using a transistor someone gave me the part number, ordered it from Mouser electronics I think, it was real cheap, do not know the part number off hand.

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