I had to replace my reverse light housing in my 72 Cutlass and I also powder coated my bumpers. My reverse lights are not working so I was wondering if the lights are grounded via the bumpers connection the light housing?
I've verified the obvious and there is power all the way to the connector for the reverse light house when the car is in reverse.

 

Yes.

 

You can run a ground wire to the light housings if you don't want to mess up the powder coating.

 

Thanks...

That sounds like a good idea,...

 

FYI, if the electrical component only has one wire, it MUST be grounded through the bolted connection. And don't feel too bad. Olds engineers initially overlooked this on the Rallye 350 back bumpers as well. Even worse, Chevy engineers initially didn't realize that they needed to run separate ground wires for everything on a fiberglass body.

 

My reverse lights have been an issue and, happens to be that the entire interior of the car is removed for new upholstery. Now is the time to look for shorts in the wiring, right?

Would a new harness be the easiest (albeit more expensive) route to go if the housings, bulbs and such look/test fine?

Also, showing my ineptitude and lack of car in my possession right now, is there one big wire harness to the rear and front OR another (or a few. ex, one that runs through the dash).

 

Shorts do not cause things to be directly inop. They cause smoke and blown fuses which lead to things being inop. I would not replace a whole harness just for the backup lights, I would troubleshoot to find the root cause and repair accordingly.

 

If the interior is out of the car, now is a perfect time to carefully inspect the wiring from the rear harness connector at the fuse box, all the way to the rear bumper. If everything works except both reverse lights, it should be fairly easy to find the problem. Get a cheap ohm meter, unplug the reverse light connector at the NSS. Test for continuity from the NSS connector (light green wire) to the light green wire at the reverse light connector. Then test the other light connector. If the wire is good, then either both light housings have a bad ground, both bulbs are burned out, the NSS switch is bad, or the NSS isn’t getting power. If I remember correctly, the reverse bulbs are powered by the turn signal fuse. Since the turn signals work, the fuse is good.

 

So i need to grind down the powder coat on the contact surface between the housing and the bumper? What about attaching a wire at that connection point and running it back to the frame also?

 

Either way works. If you plan to use the bolted joints as the ground path, keep in mind that you also need to provide a clean ground path from the bumper to the brackets to the frame. Frankly, a separate ground wire from the light housing to the body is probably easier and more reliable.

 

That separate wire seems easier. I thinking just drill a small hole and run a sheet metal screw into it, then ground it inside the trunk.

 

Don't drill anything. Just use an eyelet under one of the mounting screws.

 

[QUOTE=joe_padavano;1234221]Don't drill anything. Just use an eyelet under one of the mounting screws.


[/QUOT
Got it

 

When I have to use a ring terminal on the outside of the car, I prefer to remove the plastic insulator, solder, then cover the crimp with heat shrink. One of the few things from harbour freight that seems to work well is their marine heat shrink. It has glue that melts to seal the wire from moisture. Push the heat shrink up close to the circular part of the terminal, make sure the tube covers the insulation, and you will never have to fool with it again.