Brake/ Tail light problem

[vetteguy22]

I was following my son the other night when I noticed that when he hit the brakes the left corner went dark. (He drives an 1982 vette.) No brake or tail light. So I was checking into this weekend and found that when the tail lights are on, all light are working normally, but when he hits the brakes, the right brake light activates but the left tail light goes out and the brake does not light. With the tail lights off, and hit the brakes the left light will light, but on the tail light filament, not the brake light filament. Likewise with the blinker, it lights on the tail light filament and not the brake filament. I opened things up and checked with a test light and am getting power to what appears to the the correct bar in the socket but still the brake light filament will not light. Tried a new bulb but still the same thing. Was originally thinking it might be in the turn signal switch but now I'm not so sure. Any help would be appreciated. Thanks

 

[mrvette]

Welcome to the motley crew......:quote::bounce:


and as to your problem, I bet bux it's a bad/rusted/corroded ground connection maybe broken wire from the socket bayonet to the frame just above the exhaust pipe....

:smash:

 

[vetteguy22]

tail/ brake light problem

Thanks for the input. I checked it out this am. Ground at the frame was good, followed the wiring to the bulb socket, looked ok also. Pulled the bulb and checked the ground in the socket to the ground on the frame with an ohm meter. No continuity. Pulled the ground wire from the socket and found the ground blade was broken. Repaired that and the lights work properly. I really appreciate your help. I had thought about the ground but had kind of dismissed it due to the tail light working. I guess it my be grounded via the right tail light?

 

[MYBAD79]

Similar issue with taillights here: brake lights work, turn signals work, taillights do not work.... bad thing is that you don't really notice until somebody tells you .. I am pretty sure that I have a bad ground somewhere as well... one day I'll find the time to have a closer look ....

welcome to Vettemod by the way :thumbs:

 

[mrvette]

Thanks for the input. I checked it out this am. Ground at the frame was good, followed the wiring to the bulb socket, looked ok also. Pulled the bulb and checked the ground in the socket to the ground on the frame with an ohm meter. No continuity. Pulled the ground wire from the socket and found the ground blade was broken. Repaired that and the lights work properly. I really appreciate your help. I had thought about the ground but had kind of dismissed it due to the tail light working. I guess it my be grounded via the right tail light?

I forget which way is which on these bulbs, but you can 'back feed ground' to the circuit through the filaments of other bulbs in the circuit, and the more in parallel the merrier, until the other filaments need be lit, then it all goes out....if you could pull the lenses and look at night, you well may find the filaments used as grounds via the 'back feed'...will glow softly....like it had a bad battery to them...really dim....

:shocking:

:beer:

 

[big2bird]

Yep. The socket ground is bad. No doubt.:thumbs: