I have a 76 280 and I've converted everything but the headlights to LED. All of the turn signals, brake lights etc work fine but i have one interesting problem... If the headlights are off and I put on my turn signals, all of the instrument lights will flash as well. If i step on the brakes they light up too. The only time this doesn't happen is if the headlights are on. All of the interior/exterior lights are LED and there is an LED signal flasher installed as well but no resistors anywhere. Any electrical experts out there have .02 to share?

 

Are you sure you didn't put a bulb with an 1156 style base into a socket that needs an 1157 base?

 

yea positive on that. im thinking it has a bad ground somewhere. My car has a corvette taillight setup and theres 2 lights on each side so i used one of those trailer light converters back there to separate the brake and turn signals. I bet its back there somewhere.

 

You ever find out what's up I have the exact same problem in my 1986 300zx!