My son has a '99 Neon. He just had a repair shop replace a brake line (common problem I hear) and now his temp gauge pegs with the headlights on and sometimes with them off. I'm guessing that something got jostled when the brake line was repaired. My son (19 and at school 500 miles from me) googled it and said something about a bad ground wire which I can't seem to find when I google it. Can someone point me in the right direction?
Thanks
Mike

 

There is a ground wire on the headlight switch. Have to removed a dash panel or two for access.