After doing this myself this morning I thought I just share a reminder of a quick fix for anyone who is suffering from distorted, crackling, cutting out sound from the door speakers.
Mine started distorting, dropping out, crackling etc only during full throttle and sound returned to normal during braking. This was happening to both Front and Rear RIGHT side speakers only so it wasn't a specific door issue and my initial "Oh god, now what!" thought was "if its everything on the right side of the car, its not the individual speakers or the wires to them" so it made sense to me that it was possibly the Bose Amp instead (info below).
However, after jumping on eBay and seeing the £300+ price of a 2nd hand amp I thought to myself "You're an aircraft tech dude, if this was a plane how would you fault diagnose this issue first rather than just replacing expensive bits on a hunch?" so before I went any further I did the following and found the free, simple fix to my specific problem -
- I unplugged the Bose amp and checked the connectors (two plugs - 1 massive "zero insertion force - ZIF" connector and one '2 wires' Fibre Optic connector) then plugged them back in.
- I'm using the iPod 100% of the the time, so does the sound cut-out under other music sources like the Radio - No, it only cuts out using the iPod so the Amp is OK (whew!).
- Unplug the iPod in the glovebox, check it with some headphones (both sides play music so iPod is OK), then plug it back in and test - HaHaHaHaHa - Fixed
So if you have any "speaker" issues, check your cables, change music sources etc first. As part of all the investigation, I also rediscovered - i.e. remember I ONLY use the iPod, nothing else for the past 10 years of ownership - that not only do I have a DAB radio (makes sense TBF) but I also have a TV Tuner as well
which I genuinely had no idea I had, so I spent a few minutes watching the BBC news whilst I was parked up.Bose System Info - Whilst I had everything apart I recorded all the part numbers for the stereo. Now this is all for a 2008 car with 2G MMi, for a newer 2009+ car with 3G MMi the Amp info is different.
2008 Amp Part No - 4F0035223G
2009+ Amp Part No - 4F0035223P
2008 DAB Tuner - 4E0910563C
2008 TV Tuner - 4E0910148D
2008 FM Radio Receiver - 4F0035541L
Hope that helps!