Idiot Lights to Guages Swap?

[Chevy35512]

Hi had this same problem and after being told to test gauges, sensors, replacing the alternator 2 times,and talked to every mechanic I know and looking at all the post and wiring diagrams I found the the Monte Carlos that came with gauges have a wire with a 10 OMH resistor in it that you need for the gauges to work right. The Monte Carlos with idiot lights has a brown wire coming back from the alternator that fed through all the sensors / sending units back to the lights witch we do need now. So the answer is a 10 OHM resistor. I used a 10 watt 10 ohm NTE resistor and put it inline to the pink/black wire that feeds power to the gauges and it works great.

 

[buzz77]

I bought the GM guages to replace my GM idiot lights. The fuel and the volts seem to be working but the oil and temp are out of wack. How do I go about fixing that?

Did the same swap on my 79 GP, with the same two gauges giving me trouble. Swapped out the senders for the correct ones. The oil gauge works but I doubt its reliability. The temp gauge I originally thought did not work. The shop manual simply says to ground the wire to the temp sender and the needle should spike to the other end. On the oil, the gauge should spike by simply unconnecting it. When connected it should move back to zero position.

Anyhow with the temp coolant gauge I couldn't figure out why it didn't work, afterall the ground test said the gauge was fine. Started the car allowing the engine to heat up and taking it around the block a few times didn't do much. But after my first drive in hot weather, stop and go, it actually works just fine. So take it out for a long drive and drive it hard in stop and go traffic, it may surprise you.