L322 Battery drain problems (audio I think)

hi guys bit baffled on this one parked the car up yesterday and had no issues, left it till this evening and went to start it, battery flat! But not totally flat interior lights etc still working, just wouldn't unlock ignition so I could turn the key. Put a battery charger on and first thing that started was a loud cracking over the speakers. It's a 2003 vogue, would I be right in thinking either the dsp amp or bm54 unit may have got wet and not switching off? I've had crackling on the speakers for about a week, but only with ignition on. I've got the plastic water guard over the TVs module, Bluetooth & dsp amp to keep the connections dry.

For now I've pulled fuses 8 (I think) and 49 in the glovebox fuse box so I can see what happens next so to speak. I did also think about heater resistor issue as well but not sure if that would fully drain the battery. Or even if mine has been replaced. Heater fans are however still working. Any help appreciated

I followed a thread a few weeks back and the problem was the sat nav unit wasn't shutting down as the problem went away when he left it disconnected. As you say FSR is another common issue as is headlight wipers on the pre 05 models not parking properly or being damaged.
Dodgy battery or alternator a possibility but a process of elimination as you are already doing is the only way. The fuse buddy can be helpful in tracing a drain but can be a long process and be sure to follow correct shut down procedures before pulling fuses especially for the sat nav as I'm sure you already know.

yes to be fair the sat nav or any audio booted up, i couldn't even release the steering lock to turn the ignition on, i'm 99% sure it's either the dsp or bm54 unit but couldn't do a lot tonight was due at work and trying to start the car etc, but as i said above as soon as i put my battery charger on first thing i heard was crackling/hissing through the speakers. at that point i tried to turn the key in the ignition and it worked, but wouldn't start obviously so i left it on charge, after 20-30 mins of the car being on charge but the ignition being off & key removed i still had the hissing through the speakers until i removed fuse 49, i also removed fuse 8. i got in from work and it now starts after 5 hours charge, but i think i need to look into it further tomorrow.

just to update this, i've now found the leak it is infact the tailgate seal leaking it turns out the top right corner was not located on properly and was only on there loose, if this will fix the leak or not i shall know after a few hours rain, but i have noticed a couple of places where the water is also seeping between the glass and seal resulting in damp carpets, also where seal was not located properly. in short water leaked down the rh rear pillar behind the trim and onto the electronics, even though they were all covered with a plastic sheet, the plug nearest the rear light on the DSP amp was soaking wet, and also the adaptor harness & ulf plugs were also moist. go to say i've never seen so much water in that area the plastic sheet had puddles on it!.

Is the audio still making the noise or have you managed to dry out the electronics ?

i've not reconnected the power yet, i'm pulling the dsp out tomorrow for a couple of days in the airing cupboard to make sure it's dry in & out fingers crossed it was just the wet connectors causing issues, until i know the leak is fixed i'm not reconnecting anything, i'll prob fit the LR condom to just to make sure. but at least i know my rear 1/4 windows are not leaking.

Cool, good luck, I've saved a couple of dunked phones by drying on a radiator so you might be lucky

fingers crossed, i have noticed also the cars seemed a bit sluggish last couple of weeks, it's like driving a sports car now so may have been draining the battery for a while

You should be fine but if you still encounter problems, (when you have reconnected the amp), it would be well worth removing the covers, (obviously after disconnecting it from the vehicle first), and you can then 'scrub' the circuit boards with a clean toothbrush soaked in isopropanol alcohol, (obtainable from RS and Maplins), as this will remove any grease and dirt that may have been disolved in the water that contaminated the amp.

If you then wipe the circuit board with a lint free cloth any residue/dirt/grease can then be removed before the alcohol evaporates leaving a nice clean board.

Ideally you should clean both sides but that may not be practical and the majority of problems only arise on the track side of the printed circuit board.

You would have to be very unlucky for the amp to have sustained any damage - you would have known about it by a distinct smell of burning - exactly what happened when the CD Auto Changer, (in my Grand Cherokee), suffered water ingress from a, (self induced), water leak in my Jeep!!!

thanks martian, still waiting to see if refitting the seal has corrected the leak. so far so good. i work with electronics all the time so aware of how to clean the board. but thanks.

Sincere apologies for trying to teach you to suck eggs!!

Martian said:

Sincere apologies for trying to teach you to suck eggs!!

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But helpful to members who are not in the trade.