Weird Question with Reverse Light

[Lambskinny]

Would anyone have any idea why someone should splice in an on/off switch to the back up lights? I finally tracked down what the light green wire was on the bulkhead connector on the driver side firewall. I have a 1988 c3500 single cab. Someone wired in a trailer brake using some of the roof cab lights. They don’t work naturally. There’s also a push pull switch on that thing. Probably the product of, I know a buddy who can do that. Was a 454 but they put a 350 back in. Had cruise control but it was taken off. AC not hooked up. It had number 2 and 6 plugs backwards and number 5 was completely off when I got home with it. Fuel regulator bowl was on backwards so it didn’t seal right. It’s been fun, but I love it. Adding pictures just for the hell of it. I don’t read books that don’t have pictures.

 

[Lambskinny]

Well i found that the switch turns off the back up light because they stay on constant with the running lights. Gotta figure out how in the world the trailer brakes were installed. if the image uploaded, the blue wire and yellow connectors are part of that. The blavk and white wire on the black plug i found is the door jamb switch that isn't in there. Having a hard time finding out what the orange with black line, black, and red wire is. If anyone has the c3500 with cab clearance lights, what is the black and white wire connected to coming down from the roof? in my picture, i think it's the black and white wires in the back going from left to right. They spliced into it for the trailer brake module.

 

[Lambskinny]

If anyone is interested, in my 1988, the bottom right corner of the convenience center is the plug in for the roof lamps with a gray plug. Mine is missing. So i may just cut out the trailer brakes and find a plug to splice back in and redo the wiring for the trailer brake. i don't need it, but will be good to have if i do need.

 

[packer0440]

Well i found that the switch turns off the back up light because they stay on constant with the running lights. Gotta figure out how in the world the trailer brakes were installed. if the image uploaded, the blue wire and yellow connectors are part of that. The blavk and white wire on the black plug i found is the door jamb switch that isn't in there. Having a hard time finding out what the orange with black line, black, and red wire is. If anyone has the c3500 with cab clearance lights, what is the black and white wire connected to coming down from the roof? in my picture, i think it's the black and white wires in the back going from left to right. They spliced into it for the trailer brake module.

The wires going to cab lights are black and white, I think white is hot when the parking lights are on. Plugs right into convenience center. There is no reason to tap into those wires for trailer brakes. Maybe they thought they were splicing into the white brake light wire(?)

 

[Lambskinny]

The wires going to cab lights are black and white, I think white is hot when the parking lights are on. Plugs right into convenience center. There is no reason to tap into those wires for trailer brakes. Maybe they thought they were splicing into the white brake light wire(?

They unplugged from the convenience center, so there's no power to the cab lights. I'll have to look again for the 3,492nd time. But i just realized i need to know which wire goes where because i don't have the plug. White does make sense to be hot after looking at some diagrams because all the black and brown wires all tie together. I hope i can just rip out all their stuff and start over. If a junkyard donor don't have a plug, i'll just improvise with connectors i have. I'm still baffled on why they used those wires. i hate wiring. especially after someone else's rat nest.

 

[tpass]

nice truck!

It's a wonderful thing going through and fixing a previous owners "improvements"

 

[Lambskinny]

nice truck!

It's a wonderful thing going through and fixing a previous owners "improvements"

I think I may have figured out one part. I think the convenience center may have been replaced by one from whatever truck the 350 came out of. It was originally a 454. I’m thinking this because the roof lamps section doesn’t have the wires in the back of the convenience center. The truck would have originally had it. Or at least that’s what I suspect.

 

[Lambskinny]

Finally just found the brown wires that looked black that go to the corner lights. Tapped in to it and a ground. Got it working. New lenses and seals from 1A auto were pretty cheap. 50ish for all 5. Got a new temp, battery and oil gauge from Oreily’s. Now onto the dome and courtesy lights. The door plunger switches are out and need bulbs in the dome light. Hopefully less of a headache than the rest. The rear cargo light will be the last thing probably. May try to get a 3rd brake light integrated into a whole new fixture.