Ok. My 1986 IROC has gauge issues. When I turn in the headlights the tach and other gauges do not work. They work fine when the headlights are off? The three lights on the right side of the tac also do not work when the headlights are turned are turned on.

So I did research and someone told me to replace the headlight switch. I replaced the headlight switch, changed all bulbs, cleaned every contacts, took gauges out and reseat them...guess what it did not fix anything.

Suggestions please... it am at wits end.

Thanks,

 

Not one suggestion, hypothesis, theory or opinion? Come on man! I know it is not much to go on but someone out there had this issue. The car is bone stock and not chopped up?

 

Hi Reim. What do we know? We know the gauges work before the switch is turned on. We know when the switch is turned on and a big load is placed across the circuit the gauges act up. We know that the switch is new and should be good. Just based on this I would check the grounds all over the car as loose grounds make things go crazy. It can cause circuits to try to pull ground through the positive side of other circuits. That makes the other circuits go nuts. It is very likely a loose ground or missing ground wire somewhere. Check all grounds relating to the headlights and the gauges. Then check grounds everywhere else. I'd also check the fuses relating to those circuits. My cars make poor connections in the fuse blocks and most gm vehicles from that time did. The plastic holds the fuse not the brass contacts. Anyhow, that is what I would do. Hope this helps.

al

 

Thanks Fan. I do appreciate the input. I know electrical is tough to diagnose. I am not great with the electrical piece and a couple of shops I talked to do not want to mess with it. Very high aggravation factor.

I will start checking the ground connections. I did not think about the fuse box. Maybe I will get lucky.

Again I appreciate the feedback.

 

It could be the black ground coming off of the switch. I had a bad ground and found it by splicing into the ground wire close to the bulb and grounded it on something I could see. Once I saw this fixed it, I added the additional ground instead of tearing the car apart.

 

What up G? The black ground off the headlight switch?

 

Yeah, try splicing into that and grounding it to a good ground and see if that fixes it.

 

Ok thanks. I had to put the dash back together but will do that ground wire. I hope it fixes it and my search is done.