Strange goings on on the bootlid electrics

[gunman]

I changed my S2 for an S6 avant back in November. The car has a wierd issue with many of the electrics on the bootlid. For example:

You press the brake pedal, brake lights come on but so does the light on the ddash for the heated rear screen.

You put the heater rear screen on and the 3rd brake light comes on.

You put the rear wiper on, it takes 30 seconds to pass over the screen, sometimes stopping in the middle, again, the heated screen light comes on. Havn't checked on the brake light yet.

2 things I can think of that could cause this are a break in the loom and the live wires are shorting off each other or could this possibly be caused by a bad earth on the bootlid (like a bad earth on a trailer board when everything lights up)? Just asking in case it's a common fault (although I've never seen this one before)

Oh, and sometimes some of the buttons on the climate control don't work, I thought this was an unrelated problem until the rear wiper stopped and the display faded until it started again??

I could do with a rear wiper and a rear heated screen this time of year.

[Monkeymagic]

I would think its broken wiring on the rubber boot between the body and bootlid

[bluequattro]

Are they on same fuse?
My 80 blows dash lights, glove box and tear plate light if I slam the boot with the lights on!
Did it this morning when I forgot something
Wasn't impressed changing the fuse when it was peeing down
Have a large cache of fuses in the car for when I forget!
Will sort it when I fit my dent free bootlid

[Fat Audi 80]

Go deep on the boot lid wiring, you will almost certainly find damaged wires. Note, you will have to dig under the gluey black loom tape to see the problem.... HTH

[UrS4boy]

I changed my S2 for an S6 avant back in November. The car has a wierd issue with many of the electrics on the bootlid.

I guess you missed my early posts on C4 hatch wiring:

http://www.s2forum.com/forum/showthread.php?t=68015&highlight=hatch+wiring

And trouble-shooting a C4 rear hatch wiper issue:

http://www.s2forum.com/forum/showthread.php?t=68057&highlight=hatch+wiring

[gunman]

I guess you missed my early posts on C4 hatch wiring:

http://www.s2forum.com/forum/showthread.php?t=68015&highlight=hatch+wiring

And trouble-shooting a C4 rear hatch wiper issue:

http://www.s2forum.com/forum/showthr...t=hatch+wiring

I hadn't seen that, will be very useful tho, thanks.

[RS2junkie]

Hi,

Had similar problems and it turned out to be the wiring where it passes from the tailgate into the main body, there is a rubber bellows with a bundle of wires in it, the problem is the wires get stretched and break, then short out.....

You can buy a replacement wiring section with plugs fitted on ebay.de

I managed to repair mine and has been OK for a few years now...

I am sure it is part of the replies on here..

Good luck

P

[macspring]

A bit late in my reply, but no one beats Dave for speed and comprehensive replies, ooh and tolerance of us lesser mortals, but has to be the wires at the tailgate hinge. Go to breakers and cut out the internal underfloor looms (mint condition), from the same vintage VAG car to allow you to have the correct colour wires to splice in. Stagger your repairs at each end to avoid having a big lump in the repaired loom.

Solder the connections, and definitely heat shrink the connections. Obviously, but always worth repeating - always remember to put the piece of heat shrink on the cable before soldering the two cables together.

Take photos of everything before you start.

Kind regards.


Dave for Pope !

[gunman]

Cheers, I have a spare 80 Avant at the side of the house which can supply any wires I'll need I'd say. Weather permitting I'm going to get a look at this over the weekend.

Cheers All.

[UrS4boy]

A....no one beats Dave for speed and comprehensive replies, ooh and tolerance of us lesser mortals

LOL. I thought I responded in a precise, yet, polite manner there.

Apparently still room for improvement.

[gunman]

I finally got a chance today to get a look at this and it's all sorted now. There wasn't 1 undamaged wire in the loom!

Someone has been in there before and made a right mess. The wires had been joined inside the rubber boot between the bootlid and the car roof, of course, the solder had broken from flexing. This was made worse by the fact they'd use 6" of wire where 2" would do, folding the excess inside the boot:



I was able to disconnect the loom from the boot and pull back into the boot area. I used wires from my spares 80 tdi and put a good foot off length so there would be no joints where the wires flex in the rubber gaiter:



L]

All joints were soldered and insulated with heat shrink tubing. The new wires were pulled through to the bootlind, luckily enought, the gaiter from the 80 was the same as the S6 as the original one had split into 3 bits, probably due to the mass of cables shoved into it:






Wires joined up to the loom in the bootlid, I tried to stagger the connections so there wasn't 1 big mass:



Taped up the looms and refitted the trim, looks good as new:



Now, The heated screen doesnt come on with the brake, the brake lights work as they should and for the first time I have a rear wiper that actually wipes and a rear wash. Took over half a day to do, possibly because I couldn't feel my fingertips it was that cold out there but, it should last a while now.

[Vorsprung durch Technik]

Excellent job done there.Nice one