Electrical problem with Caravelle

You probably one of three problems with the brake lamps. You have either a bad ground connection or improperly installed bulbs or the wrong tail/brake bulb. Since youi say they're too dim, I'm thinking it's a bad ground but checking that means getting into the taillamp area so check the bulbs anyway.

Remove the access panels in back to get to the taillamps. Unclip each bulb tray (just two clips that you squeeze together) and pull out the tray. You should have a single-filament bulb in each section for the lower amber and white areas (turn signal and backup bulbs) and a dual filament bulb for the red area (brake and taillamp). Make sure each bulb is correct and seated properly and that none is blown. If the brake/tail bulb isn't seated right or especially if it's incorrect (a single filament instead of a dual filament one), it can send power back through the system from the brake light system into the taillight/instrument panel/parking lamp system so this may be what you're seeing when you hit the brakes. The brake/tail bulb is also designed to fit in only one way (since it should be dual-filament it needs to fit only one way to ensure that the correct filament is matched to the correct bulb connection). It has two little pins on the base at different heights. Match each pin to the guide slots on the socket, press in, and turn until seated. While it is designed to fit only one way, I have seen them forced in the wrong way and that could cause your problem, as could forcing a single filament bulb into a spot designed for a dual-filament bulb.

If that doesn't solve your problem, now check the ground wiring. From each bulb tray should be a brown wire that connects to the body, usually through a simple ring terminal with a screw through it. Make sure this connection is present and free of corrosion. If the brown wire isn't grounded, you have an open ground and the bulbs are trying to find their own ground through each other. I know on the driver's side one it grounds to the body right near the taillamp. I didn't notice on the passenger side but I think it's probably similar.

Hopefully those will work. From the symptoms I don't think it's a problem more serious than that...I suspect it's either a wrong bulb in the tail/brake position, improperly installed brake/tail bulb, or a bad ground. All of those things are usually fixable at the rear of the vehicle. Should have to mess with any wiring up front for that.

Once you sort that out, see if the backing lamps work. If not, check the bulbs and also the fuse for them. If those are OK then it's probably a bad switch. I'm not sure where the switch is for those though...not sure if it's at the base of the shifter lever or on the transmission...most VWs have it on the transmission housing somewhere.

Backup lights - check the switch in the transmission, then the contacts, the bulb filaments, make sure there is 12 volts between ground and the positive contact when reverse is engaged, measuse this at the light socket.

Brake lights - clean up the contacts, check to see if the centre light works

"Matt B." wrote

Thanks a lot! I am not just stupid, sometimes I am really stupid.

First I had problem with the backing-lights, while trying to fix that I exchanged the position of the backing light and the tail/brake light.

Thanks a lot for the thorough explanation. Now the most urgent problems are solved (the brake lights work). Only the backing lights are not working. That is not to much of a problem but it is probably more a more easy fix, I will do some googling about that after new years.

Happy new year and thanks a lot.

Tim

"Rob Guenther"

Thanks a lot, that was more easy said then done though. Do you have any suggestions about how I could proceed to find the switch in the transmission? For intance is that something you acces from under the car or from the inside?

Atleast the other problems are solved now, only the backing lights left. It makes sense that it should be the switch since it affects both lamps and sinc they wer both working not long ago.

Thanks

Tim

Hi Tim:

You'll find that Google Groups is your friend:

You can search for "transmission switch back up"

and you'll find the same exact question I asked a few weeks ago!

Short answer:

The switch is socketed into the top of the transmission, more or less under the engine air filter/intake. It's either a two wire simple switch (in which case it would probably still be working) or a cramped 5-pin multi switch with contacts that are too small to handle the back up lights' current reliably.

I ended up just splicing the reverse wires to a manual switch in the car, then I can turn on the back up lights whenever I please. There are better options, such as replacing the switch (not too hard to do apparently) then installing a relay to carry the back up lights' load so the little switch doesn't have to.

Best of luck!

-Antony

Ah OK. So you had a single-filament backup bulb in the spot for a dual-filament tail/stop bulbs? If so, yes...that'd cause the current from the brake light circuit to bleed over into the tail/dash/parking lamps circuit because the single center-contact on the bulb is probably hitting both contacts in the socket. Likewise, turning on your tails would cause the brake lights to activate, making it look like you had super-bright taillamps and/or the brakes on all the time.

If all the lights except the backups are working, I'd say that now it's either both bulbs are bad (but if you replaced one/both and still not working then that negates that), the fuse is blown, or the switch is bad.

"Matt B." wrote

Oh yes that was exactly what I had. I cannot imagine why I didn't see it when I exchanged them. I remember that I even looked at both lamps to se that they were the same.

Thanks a lot for the carefull explanation.

Lamps and fuse are working so I will go looking for the switch in the beginning of januar when I get acces to tools and garage again.

Thanks a lot and happy new year.

Tim

"Antony Hilliard"

I will definitley do that when the new years party is over and I have access to tools and garage again.

Thanks a lot for the infor and details. It doesnt sound to hard, seems like I will have a nice and easy task to start out the new year and my meching carrear.

Tim