taillight issue on my wife's harp-mobile

[AaronW]

All:

My wife has a 1983 volvo wagon, which I'm trying to keep on the road, since it's the only car we've got that she can get her concert harp in and out of, by herself. It's kinda on its last legs, but as long as I can make it last...

Anyway, it's got a taillight out, and I'm stumped. I've got power all the way up into the bulb housing, where the light bulb presses in. Nothing. I bought a few new bulbs, and tested it on a couple different ones, just to make sure. I even tried running a wire off the taillight wire, and touching it to the bottom of the bulb, outside the housing it fits in. Nothing there, either.

Anybody got any ideas about how to proceed? Seems like a general electrical issue as opposed to something specific to this car, so I thought I'd poll the accumulated wisdom here.

Aaron

 

[Vbb199]

I know nothing at all about vw, but to me, it sounds like a grounding issue

Is there body grounds to the frame or battery?

 

[AaronW]

I know nothing at all about vw, but to me, it sounds like a grounding issue

Is there body grounds to the frame or battery?

The whole taillight housing grounds to the frame. It's real easy to see. This guys video here:

xc_hide_links_from_guests_guests_error_hide_media

has a decent visual of the setup.

Aaron

 

[Ricko1966]

I am going to assume all the wire lead to a plug that plugs into a plastic housing with electrical contacts. Supply a ground to the base of the bulb,does the bulb light? Trace your contact on the housing from plug to bulb apply ground at the appropriate contact in the housing at the conector,Does the bulb light? Check continuity from each of the bulb contacts including ground to the connector terminals in the housing. If any fail continuity buy a new housing or fabricate a jumper. If adding ground at either point lit the bulb. Add a ground or figure out where your ground is broken.

 

[AaronW]

I am going to assume all the wire lead to a plug that plugs into a plastic housing with electrical contacts. Supply a ground to the base of the bulb,does the bulb light? Trace your contact on the housing from plug to bulb apply ground at the appropriate contact in the housing at the conector,Does the bulb light? Check continuity from each of the bulb contacts including ground to the connector terminals in the housing. If any fail continuity buy a new housing or fabricate a jumper. If adding ground at either point lit the bulb. Add a ground or figure out where your ground is broken.

You guys nailed it. What I hadn't figured out, was that the little ground contact that's on the bulb housing wasn't making contact with the main ground bar on the whole taillight unit. You can't see it, when the bulb is installed, so it doesn't jump out at you when you look at it. I attached a wire to the bulb housing, drill a hole in the taillight unit so I could get the wire back out of there and onto the main ground bar. Presto, problem solved.

Thanks guys, you sniffed it out.

Aaron