S3 (8L) Bose Sub broken - any help?

[dekington]

Hi Guys,

Been reading around these parts for a while now and i've got stuck on something i could do with a little help on.

The bose sub in my 2001 S3 has stopped working. First it was coming on and off randomly for about a month or so (a heavy bump would often do it), and now its totally off 100% of the time. Following some advice from AndyMac i read in another thread, i 'borrowed' a multimeter from work and i could see that the sub is getting perm +12v, and the remote on is showing at 11.38v..

Based on that, does anyone have any suggestions as to where i should go from here? I was keen not to have to put it into a garage only to pay a fortune for someone to spend a couple hours literally looking at it, so was trying to fix it myself - but is this the end of the DIY road or is there anything else i can do?

Cheers!

 

[AndyMac]

It's most likely a loose connection or dry solder joint on the amp inside the sub enclosure. Seen quite a few of these issues on the Bose subs.
You'll need to remove the enclosure & take the front off to get to the wiring on the amp. Check there's nothing obvious hanging off, then take the amp apart and resolder the main connections on all the main components. Takes about 15minutes, but a lot longer to get the enclosure in & out in the first place. If you don't fancy doing that then send it to me and I'll fix it for the price of the P&P or buy one off ebay:
http://cgi.ebay.co.uk/a3-sub-woffer...ryZ18805QQrdZ1QQssPageNameZWD1VQQcmdZViewItem

 

[dekington]

Thanks Andy. I guess its goodt to know that its something you've t least seen before, so there is hope i mightbe able to fix it. Thats what i feared - that i'd have to take the whole thing out! Is removing the boot trim easy enough to do? I'm sure i read before that it was practically a major operation..

 

[AndyMac]

Just to get the sub out is fairly straight forward as you only need minimal space.
Remove the boot liner
Remove the 3 cargo anchors (2 on the boot lip and the one remaining one on the rear panel).
Remove the 4 Torx screws holding the boot lip trim. Swing the boot lip trim up and out, there are 2 black plastic things that generally fall out of the trim at this point, they slot back in either side of the underside of the trim piece.
Remove the stupid plastic screw up inside the cubbyhole holding the trim to the top curve of the boot lip near the rear lights.
At this point the only thing holding the trim is a single metal spring clip on the curve of the boot lip & the boot lip rubber. There is also a hidden screw underneath the rear speaker panel, but leave this as the boot panel doesn't have to come all the way out to remove the sub.
Release the trim from the cargo anchor aread & then pull hard on the remaining spring clip.
The trim piece should now be able to be prised away leaving enough room to get to the sub.
The sub is held by just 3 fairly obvious bolts but does need to be wiggled out and the wiring loom running across the top prised out of the groove and released from the enclosure. Think there's a white push fit fastener at the back you need to pull out to completely free the loom.
Then just remove the front panel of the sub. When refitting be careful not to overtighten the middle Torx screw on the righthand edge of the enclosure, as this has a tendancy to break the plastic on the enclosure, which will then fart badly unless fixed with copious amounts of Araldite beforehand.
When refitting ensure you extract the metal spring clip from the boot lip and reinsert in the trim.
Should take about 20 minutes, bear in mind Audi will charge you £100+ just to remove & refit the sub + about £450 for a new unit, so it's worth an hour or so doing it yourself and repairing a simple dry joint.

 

[dekington]

Cheers Andy - Thats in-depth! Appreciate the help, i'll try and get to work on it in the daylight on Saturday.
Presumably all the instructions will make perfect sense once i'm working on it - at the moment it sounds quite daunting! I had a quick search but couldn't see any previous threads with photo's of this so hopefully it should go ok..

Thanks again!

 

[AndyMac]

PM me your email address and I'll send you the instruction manual

 

[dekington]

Andy - i was able to get the car in my garage tonight and take the boot apart. Indeed the solder on the connection where the earth meets the pathetic little pcb had totally corroded so it was quite easy to spot. Man that amp is embarrasingly small eh!?

Anyway, thanks for all your help - saved myself a good bit of money if a garage had to look at it.

 

[AndyMac]

Cool, a garage would have just replace the whole sub, so yes probably £600 all in.
Great result!