Temp & fuel gauges - what am I overlooking?

Uncle Bob said

I cleaned the contacts under the gauge nuts, ensured there was continuity between the contact and the pins, and cleaned things with contact cleaner. I took some photos but TBH there was nothing to see.

FWIW I use the same ground wire that I added between the cluster and dash frame as the ground for these tests, so I know that's OK.

I expect to have the pots to do a better test today, but after the test with AA cells worked yesterday, I'm skeptical that I'm going to find anything wrong on the cluster end of things.

I think this is one reason why people end up with those ugly (IMO) digital dashes.

Click to expand...

Ok.
Next step before you put the cluster back in the car.

You need to verify that the IVR is working.

Hook up the cluster to 12 volts as you did earlier.

To incorporate 67Dart273 and Redfish procedures as well, connect one of the test resistors resistor to the sender wire of both the fuel gauge and the temp gauge .

That would be the first gauge terminal in the group of 4 looking left to right and the 4th terminal in the pic. Make sure the other end of the resistor goes to ground.

If the IVR is working, you should see the pointers deflect.

If not, I'm going to go out on a limb and say the IVR or its socket is defective.

Reasoning.

1. You have established by your diagnostics that the vehicle wiring is working properly by using continuity tests.

2. The gauges seem to work properly and are deflecting with a momentary short to ground.

3. You have removed the circuit board, metered all the traces and checked the pins .

4. You have removed the cluster from the car and the same problem exists. The problem therefore has to be in the gauges, the circuit board or the IVR. There's nothing left.


The common thread here is the lack of output voltage from the IVR which we established at the beginning of this thread.

I am certainly open to constructive criticism here folks if it helps finding a solution.

What say you guys??