Hi!
I'm troubleshooting my iffy backup lamps...
sometimes they work sometimes they don't...

or so the lamp monitor says.

i'm getting pictures of the wiring... maybe something is wrong.. .i tlooks like someone has tried to fix it before.



-adam

Next time it beeps at you, leave it in Reverse, set the parking brake, get out and look. You could have an intermittent bulb flaking out on you.

I see your photo but I'm not sure what you're referring to there; those contacts look pretty good. What am I missing?

-- Andy

Oh, wait a sec... I see now. That looks like a double-contact base, but according to the manual, a '93 backup lamp uses a #1141 bulb, which is a single-contact base.

Yup, something weird there...

-- Andy

That white lead in the pic looks as if it is cut off, dead ended. What'* up with that?

Okay, I think what we're looking at here is an aftermarket replacement 2-conductor socket (well, 3 if you count the ground connection on the side) for a dual-filament bulb. The brown conductor is the standard color for a GM running (tail) lamp exterior lighting circuit; the white one looks like generic color coding for what would be the brake lamp circuit, whose color varies from one GM model to another, depending, among other things, on whether the car uses the same circuit for both braking and turn signals, or whether like the Bonneville, it has a separate brake lamp circuit.

According to the manual, the backup lamp is supposed to be a #1141 bulb, which is a single-contact base like a #1156, not a dual-contact base like a #1157.

The brown wire runs out of sight off the edge of the photo, but I'm thinking it may lead to a spliced connection somewhere.

This is all guesswork on my part; maybe the original poster can get back to us here.

-- Andy

Ah-HA! I've got it!

Take a _real_ close look at that photo. In between the dual contacts, you can just barely see the center contact of a _single_-contact bulb. This looks like a case of the correct bulb getting jammed into an incorrect replacement socket.

This could be made to work, sort of, by installing a #1157 brake lamp bulb in place of what'* there; however we can see that the brown wire has been connected instead of the white one, and thus the taillamp (low-intensity) filament will light up as a backup light, instead of the brake (high-intensity) filament. I suspect the reduced current flow needed to light the taillamp filament instead of the brake lamp filament is what'* triggering the Lamp Monitor, which thinks that the (original) backup lamp has blown, or is at least running on reduced power for some reason. Disconnect the brown wire and connect the white one instead, put a #1157 bulb in there, and it should work.

What does the socket of the other backup light look like? Somebody should check to see whether that one'* screwed up, too.

-- Andy