Rear wiper & electrics problems...

Hi there,

i just registered, i have 55 plate A3 2.0 TDi S-Line Quattro, great car... however...

my rear washer stopped working a month or two ago, so i just stopped using it... then my rear speakers suddenly stopped working for no reason (haven't worked since), then yesterday the wiper just started going by itself (even when in the off position) and later yesterday i started getting a warning that the rear right fog light is out.

So i had a look through this forum (been reallu helpful by the way) and discovered that the rear wiper motor assembly can be the source of a number of issues. Using this thread:
http://www.audi-sport.net/vb/a3-s3-forum-8l-chassis/10646-heres-why-some-peoples-rear-wash-wipe.html

I was able to have a look at the motor and saw the tell-tale gungy brown sludge dripping from the unit, so i disconnected it (the electrics) while i wait on a new assembly to replace the faulty one, since it's really annoying (not mention embarrassing) driving around with the rear wiper going full tilt!

I assumed that the rear fog light was genuinely out, so after disconnecting the wiper motor, i replaced the bulb (old one looked OK) first time i switched on the ignition, no problem and the bulb worked, second time i got the error again, and the bulb didn't work, so i changed the bulb again in case the bulb had been faulty, this time error straight away, and the bulb didn't seem to work.

I understand the rear speakers are driven by an amp located in the boot. Is it possible that, the problems with the rear fog light and rear speakers\amp are somehow being caused by the rear wiper motor? I haven't seen anyone else report similar issues when they've had problems with the rear wiper motor and it seems strange that out of the whole rear light cluster only the rear fog light would be affected.

I could see how if i kept using the rear washer and the boot was full of water it could possiblly cause a short somewhere, but to be honest, i've been pretty careful since it stopped working and it's actually pretty dry in there, just a little brown drip on the unit itself...

any help or advice greatly appreciated! not really sure of where to go next, short of going to the dealers, but i'd like to avoid that if i can!

thanks.

i forgot to add that the car sat for about a week over xmas, and when i went to start it, the battery was completely flat and required a jump, been fine since, but i've been using it daily since then. I would not expect the battery to go flat after just one week, could this also be an indication that there is a short somewhere?

i think i'll strip out all the boot trim so i can see what's wet and get to the amp, maybe get some WD-40 in there.

I understand from:
http://homepage.ntlworld.com/h5djr/elsawin/luggage compartment side trim.pdf

that i need to remove the rear seat bench, anyone have a guide on how to that? i couldn't find anything on how to do it anywhere on here. Any ideas on "Remove rear cross panel trim" on a quattro? i think i can manage the rest.

I take it a replacement amp is a dealer only item?

cheers.

by the way is it the same part number for the rear amp for sportback and 3-door? (mine's a 3-door):
8P4035382B
AUDI A3 SPORTBACK REAR SPEAKER AMPLIFIER 8P4035382B NEW | eBay

and is this the correct part number for the rear wiper assembly:
8E9955711E
Genuine Audi - A3 2005-2011 - Rear Wiper Motor | eBay

thanks

actually i think this must be the correct rear amp:
8P3035382D
AUDI A3 8P SPEAKER AMPLIFIER 8P3 035 382 D GENUINE BLAUPUNKT | eBay

bidding on a rear amp '8P3 035 382 D', hope it fits...!

@ports: my plan is to remove all the trim, dry everything out, replace the rear wiper and rear amp and see what happens, i'll let you know if that works!

just picked up a second-hand rear amp on ebay for £30:
AUDI A3 8P SPEAKER AMPLIFIER 8P3 035 382 D GENUINE BLAUPUNKT | eBay

@moag: thanks, i think the one i got should fit (out of a 2008), but would be nice to know for sure, probably won't get round to getting mine out till the weekend.

@moag

I'm hoping it will fit! i'm pretty sure the form factor should be the same from 2005-2011, the last character in the part number is like a revision number, newer internal components and SW. Not sure if this is true, but just guessing, worst case, i'm sure i could sell it on ebay again, worth a try at that price anyway!

Also pretty sure that the sportback amp is different from the 3 door:



will let you know if the one i got off ebay fits or not!