I've replaced all exterior and interior wiring harnesses in my 87 IROC with the harnesses from a 91 Z28 (as part of my speed density conversion).

The only bug I cant seem to locate is; whenever the brake pedal is depressed, the exterior turn and running lights come on and the dash lights light up. Any ideas or suggestions? Please give it a shot.

W

 

the first thing to check are the brake light bulbs, you may have a bad one.
pull all of the brake lights & hit the brake, if everything is ok, put the bulbs back 1 at a time till it does it again.

 

The usual rule of thumb is that if things that aren't supposed to light up do light up, it's a bad ground somewhere.

Ground wires are something that I hate because they are scattered all over the car and can never be found easily.

Good luck hunting.
Lou

 

I think that I've solved it the trial and error way... In the back of the car the Brown wire from the head light switch was wired to the black hatch release ground. Battery on a ground wire. Brilliant.

Thanks for your input guys! Always appreciate the feedback and advise.

W