76 F-100 Electrical question

[hp246]

I rewired my F-100 Flareside PU. Had major probelms. Turned out that a major part of the problem was no ground on the headlight switch. Seemed to take care of 90% of the problems. Still having problems with the left rear tail light. Turn signal works with lights off. With lights on, left turnsignal causes left rear tail light to go out. Same with brakes. No problem with the right tail light.

Seems strange, cause the taillights run from the headlight switch to the left side, then from left to the right.

Also noticed left turn signal seems slow when its working and left tail light is dimmer than the right. Have changed bulbs, new housing, grounded bed to frame. Amy thoughts?

[denrep]

Howdy hp246,

I'm surprised that the old plunger headlight switch needed a ground.

However, I do think that your left tail-lamp socket has ground issues.
The tail lamp works without a ground when the brake lamp is off because the tail filament is able to ground back through the brake filament, until the brake circuit is energized. Vice-versa for the brake lamp when the tail-lamps are off.

Test by grounding the exposed brass of the lamp base.

Good Luck

[hp246]

Thanks Denrep. Yeah, I'm figuring the ground too. The tail light assembly grounds to the bed, as it hangs to the side.

[hp246]

Too much powdercoating Denrep. 1/2 hour with a dremel tool and we are good to go.