I don't know if I have a short or what it is. The instrument cluster works fine when driving until I turn on my headlights, After about 5-10 minutes of driving with the lights on the in dash light in the tach will dim and the tach will no longer read, it sticks and 20 or sometimes pegs out, The oil pressure gage also drops. If I turn my lights off, the tach will pick up and read properly again and the oil pressure gage reads again. I have know idea what causes this. I hate electrical problems.

Also My heater and vent only works on defrost no matter where the control is. Any ideas?

Thanks

 

I have the same problems on my 86' Z28 if someone could point us in the right direction that would be great.

Thanks,
Jay