Had water in passenger footwell and now my audio’s stopped working c216/w221 2011 HK

[v8vroom]

Sorted out the water ingress (I checked the sponge underneath and it’s no longer wet), everything else works thank god apart from the audio and radio. Checked the fuses in all three fuse boxes and they’re fine. I’ve opened up the amplifier and aside from 2 black dust patches/spots it seems okay but I could be wrong.
Bluetooth still connects to my phone. Navigation still works (no audio). Aux doesn’t work. All radio stations say “device not available” and occasionally “no service” when I fiddle with the components in the trunk.
Could it be the auxiliary battery (no lights on the dash) or the wiring? How would I diagnose this?

 

[Finbob]

All of the symptoms you have mentioned match my experience on my 2007 W221 with the Harmon Kardon system. The cause was the HK amplifier - over the years they suck up dirt from the road. There are places you can get the amp repaired, but my understanding is that these repairs are often only temporary. I had my amp replaced by commandonline in Lightwater. Be prepared for a hefty bill, I'm afraid - if it is indeed a broken amp.

 

[v8vroom]

All of the symptoms you have mentioned match my experience on my 2007 W221 with the Harmon Kardon system. The cause was the HK amplifier - over the years they suck up dirt from the road. There are places you can get the amp repaired, but my understanding is that these repairs are often only temporary. I had my amp replaced by commandonline in Lightwater. Be prepared for a hefty bill, I'm afraid - if it is indeed a broken amp.

All of the symptoms you have mentioned match my experience on my 2007 W221 with the Harmon Kardon system. The cause was the HK amplifier - over the years they suck up dirt from the road. There are places you can get the amp repaired, but my understanding is that these repairs are often only temporary. I had my amp replaced by commandonline in Lightwater. Be prepared for a hefty bill, I'm afraid - if it is indeed a broken amp.

Could be the amp but I just find it weird how this happened exactly when I had the water ingress in the passenger footwell. So I’m thinking it could be wiring too I’m wondering how I would diagnose that before going for the expensive amp repair.

 

[Finbob]

Could be the amp but I just find it weird how this happened exactly when I had the water ingress in the passenger footwell. So I’m thinking it could be wiring too I’m wondering how I would diagnose that before going for the expensive amp repair.

My personal experience is limited to what happened to my car, but one thing the guys at commandonline asked me was whether my car had been jump-started - it hadn't as it happens. I wonder whether a shorted connection might have the same effect. I would give them a call - 01276 451579 - they are incredibly helpful and have a great deal of experience with these problems.

 

[v8vroom]

My personal experience is limited to what happened to my car, but one thing the guys at commandonline asked me was whether my car had been jump-started - it hadn't as it happens. I wonder whether a shorted connection might have the same effect. I would give them a call - 01276 451579 - they are incredibly helpful and have a great deal of experience with these problems.

Thank you for the number Finbob. I called and they couldn’t diagnose it over the phone and told me to come in for £120. He also agreed it’d be a weird coincidence for the amp to go out the exact time I had a water ingress (not in the boot). Said it is definitely possible the optical fibre wire may be damaged under the passenger footwell. In the meantime I’m going to clean my amp, reinstall and check if I get a red light in my DAB radio optical wire as I wasn’t getting one previously, maybe that’ll indicate if I’ve got a damaged wire.

 

[Finbob]

Sounds like a plan. Good luck!