The Stovebolt Site Forums The Shop Area The Electrical Bay Dome Light Help ! ! !

The dome light of my 1958 1/2 ton will stay on all the time when it is connected. I have checked out the switch and it seems to be ok. The only thing that I can think of is that there is no gasket seperating the metal light from the metal of the truck. Could this be it? Thanks

8thairforce,

That could be a possibility, but I find it tough to believe Detroit relied on the gasket to insulate the fixture. My guess would be the wire from light to door switch has found a ground through wear or pinching. Does this sound more plausible.

EDIT. This is assuming this truck has a door switch!

Stuart

8thairforce,

Poking around in this forum revealed this...your dome light is powered on one side and is grounded through a rheostat in the light switch on the other side. This would mean that the rheostat supplying the variable ground is defective, or that the wire is finding ground before it makes it to the switch. It would seem to me that the lamp holder proper must be insulated in the assembly and shouldn't rely on the entire fixture to be insulated from the body.

If you can identify the dome light ground wire at the light switch, you can disconnect it, and if the light goes out it means the rheostat is bad...if it doesn't, it would indicate a short to ground in the wiring somewhere.

Stuart

what Stuart said ... the 2nd time
the switch provides ground the light has power alla time

Bill

No door switch. According to the headlight switch wiring there are two wires from the headlight switch to the dome light a white one and a ribbed white one. The white goes to ground while the ribbed goes to the switch. I disconnected the white one (ground) and the light still stays on no matter what position the headlight switch is in. If I understand you correctly I am looking for a short in the ground wire ( white one ) somewhere. Thanks

the white wire goes to a ground terminal on the switch, which actually gets it's ground from the rotary knob, one way dims the dash lights, full the other way puts a ground to the dome lite - the other wire is supposed to be orange, maybe with a white runner, and it goes to the switch terminal labeled "D" as in dome, which should be hot anytime

if you disconnected the ground wire from the switch and the light stays on, then you've got a short along the line somewhere, an ohm meter from the switch end of the wire to the light socket should confirm that - prolly a wear spot up the windshield pillar which is pretty raw inside, but it may be at the light

Bill

Thanks my friends. I'll let you know what I discover.