I recently bought a 1987 IROC and it need some work. The gauge cluster is all weird. With the lights off, everything "seems" fine. when driving around 55mph, the RPMs are only around 1500 to 2000 and the oil pressure is below half(I've never had a V8 car or one with a oil pressure gauge, so I assume this is right). the Temp gauge seems stuck in a really high possition, it never drops and the gas gauge will only move from full when it's really low and you hit the brakes.

With the head lights on, the high beam indicator and the turn signals light up, the RPM, Oil and Battery gauges all go to Zero. When I use a turn signal, the right arrow flashes and the RPM and Oil gauge needles jump up and down with it. Also, when you use the high beams, the indicator turns off and all but one of the dash back lights come on.


Any suggestions?

 

Sounds like a typical 3rd gen gauge cluster! lol

 

Did you take the cluster out to see if everything is done correctly. My gas gauges isn't working proper either. It jumps up and down when I'm driving and when just idling it moves very slowly up and down. Try taking the gauge cluster apart and making sure everything is snapped in. I need new sending units for the temp and oil gauges because I just swapped my base model cluster for one with a z28 tach.