Last week I hit a bump and the guages stopped working (dash lights worked normally). Pulled everything apart and found that the printed circuit was in really bad shape (one connector was nearly corroded through). Just finished replaciing it with one that's in good used condition (the old when pretty much fell apart when I removed it). Now everything works fine until I turn the lights on. Then all electrical guages stop working, the turn signal indicatiors on the dash come on (they do blink off when I use the turn signals) and the dash lights don't work. One additonal thing, with the lights on the tach reads zero, oil pressure, volts, and fuel read zero, and the temp guage max's out (actually goes all the around and points straight down). Any body got any ideas as to what I missed?

Could be a grounding issue except for that pesky temperature gauge.

Are the voltage supply wires to the pod in good shape or overheating?

Is the circuit board off a car with gauges or idiot lights? I don't know but there might be a difference.

Temperature gauges measure the resistance from +12 supply to ground through the sending unit. The sending unit is a thermistor and when cold has high resistance that lowers as it is heated. So a gauge that's reading that high sounds like when the light are turned on it's grounding something on the circuit board that's not supposed to be grounded. I don't know what would happen if the voltage dropped significantly on the temprature gauge. :?

I'm starting to think it is a grounding issue. I removed the fuse for the panel lights, and everything works mostly normally (the guages "blip" a little when the turn signals flash). I'm thinking that the power to the inst. lights was feeding back through the guages and indicators (turn and high beam). and causing the problem. I'll be pulling it back apart this weekend and checking all the connections. BTW, I've got guages not idiot lights and the "new" printed circuit matchs the old one (only not in peices).

I recently had some electrical work checked on my '75 el camino . My turn signals would not work but I had taken my steering column out to replace bearings and tighten it up since my hazard lights were not working (dry rotted) I replace the signal wiring harness assembly. It was above my head so I took it to a nearby shop were they discovered a short in the electrical harness on the steering column underneath the dash. Just food for thought good luck BTW - I installed guages to replace the idiot lights also I found a cheap set at Harbor Freight and of course they went on sale after I purchased and installed mine I did replace the amp meter w/ a volt meter I placed the triple set where the analog clock would have been after a little modifications.

Pulled everything back apart yesterday (Saturday). There was a bent pin on the connector behind the instrument panel. I think this was either the instrument ground or the panel light ground (it had continuity back to ground). Straightend this out and things got better. After shiming the connector out with peices of vacuum hose (I think I saw that on a differnt thread in this forum) and putting the pod on and off about two dozen times, I got everything working normally except the oil pressure guage. I decided to quit while I was ahead and installed an auxiliary oil pressure guage. Life is now good. Thanks for everyone's input

I love happy endings!
8-)
But those pesky problems never quite leave me alone.