Hello everyone. I'm new to this forum -- just purchased an '87 IROC with the 350 TPI. My problem is kind of strange. At night, when I turn the lights on, the tach and oil pressure gauge both quit working and the right signal marker lights up on the dash. During the day, the voltage reads low on the gauge, and sometimes the volt gauge just starts bouncing around and going crazy. Only the right side of the gauge cluster seems to be affected. Do I alternator problems or is there a wire grounding out somewhere in the gauges? I does any voltage checks yet -- the car had a new battery installed at the dealership where I bought the car and a new belt (smog pump is bypassed).

Sound like you should be chasing grounds. You probable have a bad one somewhere. Good luck there I have seen a ground in the trunk of a mopar make the radio go nuts

i agree with bilms01, look behind the instrument panel on the left hand side of the steering cloumn bracket for the ground. if you have a book, its called the G200 ground.

on the "right signal marker lights up on the dash", if your talking about the turn signal indicator, look for a ground problem, a bad connection, or a bad bulb at the right front turn signal.

Thanks for all of the information. I'll have to dive into the wiring and try to sort the problem out.

ever find a solution to your problem?

Anymore info on this problem. My problem sounds very similar. None of my gauges are working anymore(only the mechanical speedo). The gauge fuse in blown under the dash and blows soon as its replaced. My voltage gauge use to bounce around before everything quit. And when I turn my headlights on the headlight alarm or something constantly beeps. I pulled my gauge cluster out. Everything visually looks ok. I guess my next step is to measure the resistance across each gauge on its own.