1972.Fargo
New Member
Hi all, I'm trying to fix a problem on a newly acquired 1998 C1500, the 3rd brake light will not work. I've done some diagnosis and here's my findings, the top right terminal (blue+white stripe), which I've determined to be the cargo light terminal, gets good power, but all the other terminals are acting basically like grounds, however (this is where it gets confusing to me):
the top left terminal (white) shows 0.21 volts when tested with the bottom left terminal (also white),
the bottom right terminal (black) gets 0.18 volts when tested with the bottom left terminal (also white),
and the top left (white) and bottom right (black) terminals show 0.02 volts when tested with each other.
I'm guessing that means my brake light wire has shorted out somewhere, but I'm not a pro at electrical diagnosis.
I've cleaned up the corrosion on the housing and now it gets good power to the cargo lamps, it doesn't get anything to the brake lamps. The rear brake lights both work great. Any insight would be appreciated.
the top left terminal (white) shows 0.21 volts when tested with the bottom left terminal (also white),
the bottom right terminal (black) gets 0.18 volts when tested with the bottom left terminal (also white),
and the top left (white) and bottom right (black) terminals show 0.02 volts when tested with each other.
I'm guessing that means my brake light wire has shorted out somewhere, but I'm not a pro at electrical diagnosis.
I've cleaned up the corrosion on the housing and now it gets good power to the cargo lamps, it doesn't get anything to the brake lamps. The rear brake lights both work great. Any insight would be appreciated.