2G Stock oil pressure gauge/light

[roadsalt]

I've been at this for a full day and still at a loss. When I bought my car the stock oil pressure gauge worked. It hasn't for a while now. So far I have replaced the sending unit, swapped the oil light/gauge wires, taken apart the gauge itself and have not found what the issue is. Here is what I know so far:

- wire from gauge sending unit matches wire into cluster (yellow w/ red stripe)
- same for oil light (yellow w/ no stripe)

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- Resistance across the gauge reads 40.5 Ohm. This is within the 42+-2 Ohm spec.
- Oil light does not come on even when sending unit wire is grounded
- No continuity between cluster pin(40) for gauge and sending unit wire (should there be?)
- No continuity between cluster pin(34) for light and sending unit wire (should there be?)
- Cluster pin for gauge to ground reads 0V when car is running (I know there is oil pressure, should it be showing a positive voltage?)

On the back of the cluster there are 2 leads to the oil pressure gauge. One goes to the oil pressure gauge pin and the other goes to what appears to be a ground for multiple of the gauges. Where does the gauge power come from?

so far I'm thinking the harness is pinched or wires otherwise damaged between the sending units and the cluster.
this is the only needle in my cluster that's not working and I want it and my oil light to work because I have to drive the car across the country in a few days. I am aware I could get an aftermarket gauge but I want my stock one to work. It's not precise but I will at least see it drop off and shut down if my oil feed line breaks for example. If anyone has a decent idea how the gauge circuit actually works let me know it would be much appreciated. I'm about to take the whole dash out again to check the wiring.

 

[NOSLO2PT0]

Why not just go buy an aftermarket oil pressure gauge and get a 100% accurate reading vs some arbitrary voltage reading?

 

[roadsalt]

Why not just go buy an aftermarket oil pressure gauge and get a 100% accurate reading vs some arbitrary voltage reading?

I will. I want my stock one working though. It's the only thing in the cluster that doesn't work.

 

[dustyboner]

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besides that,
i would take a close look at the copper strips that make contact with the harness connector. make sure none of them are de-laminating from the plastic.

 

[Kryndon]

Why not just go buy an aftermarket oil pressure gauge and get a 100% accurate reading vs some arbitrary voltage reading?

Mr. Mike, Mr. Roadsalt explicitly said:

"I am aware I could get an aftermarket gauge but I want my stock one to work. It's not precise but I will at least see it drop off and shut down if my oil feed line breaks for example."

He's trying to troubleshoot and fix his issue rather than start swapping parts.

Also, from what I understand, OP does not have continuity on his gauge wire, and he should. There very well might be a break somewhere along the wire. Also, double-triple check that you didn't mix up the wires/connectors on the gauge and sending units. Seen it happen too many a time.

 

[roadsalt]

Update: I fixed it. Will share what I have learned with photos later. Thank you all for your input I appreciate it a lot

 

[Kryndon]

Update: I fixed it. Will share what I have learned with photos later. Thank you all for your input I appreciate it a lot

Don't leave us hangin'. Let's give this thread a nice closure for people in the future.

 

[Justin DuBois]

I don't have that light anymore () I have a different light.

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It might interest you to know, I replaced my entire gauge cluster BECAUSE that little light didn't even work when it needed too. I mean, the light was functional, but the engine melted all its bearings into little sheets of foil in the pan before the load got so high that the engine just could not keep rotating. The whole time I'm looking at the stock cluster wondering why I'm loosing power, and why the stock boost gauge (its actually a load meter) was creeping up a highway speeds.

-J