hey guys i have a 1992 f350 4x4 crew cab and my third brake light doesnt work. i replaced the bulb and it still didnt work so i decided to test the terminals with both a 12v tester and a standard voltmeter..nothing. Anyone know what could be causing this ? i have my dome light power wires cut trying to fix an issue with them could that be causing this ?

 

Does your cargo light work?

 

No sir it does not

 

A 92 would not have a third brake light. The first year for that is 94. If it is a single clear lense, it is a cargo light. Does it come on when rotating the headlight **** to the left?

 

i will check that tomorrow part of the reason i havent is cuz i couldnt figure out how to turn it on in the first place lol Thanks

 

If it doesn't come on with turning the dome lights on, and the bulb is good...it's likely a ground issue. Moisture seeps in from around the seal when it cracks and corrodes. I had that happen with my 1989.

 

So i tried rotating the **** to the left and it wouldnt roatate at all. With the hesdlight on rotating it to the right dims the dash lights and to the left. Brightens them up

 

I agree with Texasguy, the high mount brake lamp for F-series trucks was not available until 1994. But you do have a wiring issue for the cargo lamp function.

 

yea its a cargo light. But ok i figured it was something like that. So when the dome/interior lights are on that should be to ? Makes sence cuz none of my interior lights have worked since i bought the truck... i cut the wires where they come up under the dash to the switch and directly applied 12v to the light and only got a very dim light So i think theres an issue between there and where the lights are