Gauge issues?

I've typed this about a thousand times

STOP thinking of the gauges as 'parts' and START thinking of it as an "end to end system."

Picture in your mind how the long path of the circuit is laid out

FIRST the cluster MUST receive "good" solid battery voltage.

This means the vehicle's harness, bulkhead connector, ignition switch and connector, EVERYTHING "before" the gauges and clusters must be up to par.

Voltage comes to the cluster connector / PC board pins. Don't "assume" they are OK, actually check or repair them. CLEAN them, resolder them. CHECK that you have good battery voltage at that point. I don't mean a test lamp, I mean actually and critically measure it with a meter. Should be nearly EXACTLY the same as battery voltage.

The IVR. Replace it with a modern solid state one, such as RTE

The IVR SOCKET. The IVR fits into springy brass fingers crimped into the board, BUT those fingers may NOT be making good contact with the board traces. Solder jumpers across.

The gauges. The gauge studs may not be making good contact with the board, loosen tighten the stud nuts several times to scrub the board clean, and / or replace the nuts

the gauges themselves. Might be out of calibration. You can easily check them, AFTER repairing other issues, and before installing in the car, by using resistors to substitute for the senders.

The senders. These individually leave the gauge studs, go back out through the board connector pins, and in the case of oil (if equipped) and temp, go through the bulkhead connector, ALWAYS a suspect. Last, suspect or at least check the sender connector

Fuel.......same deal.......goes through the kick panel connector on the way to the rear, and that connector could be a problem, although probably rare. And the connector at the tank can be suspect.

Of course the senders themselves, or bad sender grounds.........which is why, once again, you test it AT the sender connectors with your substitute resistors.

Test resistors. You don't need to build this. You just need at minimum, a mid scale test resistor, and if you can, resistors for full scale and the bottom of the scale. That means 73--75 for MT/ cold, 23--25 for mid scale, and 10-15 for full scale.

For example, for mid scale, go to Radio Shack and buy 1 package of four 100 ohm, 1/2 watt resistors. Wire all four in parallel which gives you 25 ohms. When hooked in place of a sender this should give you 1/2 (mid) scale on the gauge under test

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