Water Temperature Gauge Not Working

I try to get you guys to think of the gauges as a "complete end to end system" rather than "this works" or "that doesn't"

Here's some of what was wrong with my 67 cluster...............

Power comes to the cluster warning lights and the instrument regulator via "ignition run" from the key through the harness to PC board connector

The harness side of the connector can be loose, broken corroded.

On mine, many of the PC board pins were loose or broken. You can repair them, but mine were so bad that I abandoned the original connector, bought some "Molex" style connectors from Rad Shack and used them. I soldered wire pigtails onto the board traces down below the original pins.

On mine, the IVR was bad, I ordered an RTE replacement.

On mine, the board contacts into which the IVR plugs were NOT making contact with the board traces. I had to solder jumpers from the brass finger contacts to the board traces.

The gauges have "fake nuts" on the gauge studs. Replace these with real nuts and loosen/ tighten them a few times to scrub the connection clean.

Revisit the PC board connector where the sender wiring exits to the harness.

If at all possible, test the cluster out of the car

After reading on this board, I added a dedicated ground pigtail to my cluster, about a foot long, and bolted it to the column support brace

You can test the gauges, temp, fuel, and oil (if equipped) are all the same movement.

Go to RadShack and buy some resistors, you want 11-15 ohms for "full" 23-25 for 1/2 and 70-75 for empty

For example, buy a pack of four 100 ohm, 1/2 watt resistors and wire all four in parallel. This makes a 25 ohms resistor which you wire from either temp or fuel gauge sender to ground, turn on the key, and let it sit for about 1 minute. This should give you 1/2 scale on the guage if the IVR is OK and the gauge is still accurate.

Last don't discount problems in the harness. The temp (and oil if equipped) both go through the bulkhead connector, so THAT is a possible problem. The connector right at the sender can be a problem, and of course the sender itself can be bad or out of calibration

For fuel, the wiring goes through the rear harness kick panel connector, not commonly a problem but it COULD be.

and --------the tank sender must be grounded, and the sender must be correctly operating. Also, it seems that many? most? of these repop senders are not very accurate.