Lots of electrics problems - please help!

[Swd80]

I have a 2007 W204 (RHD) C320 CDi that I've not used much at all for the last 2 years as I now have a W213. When I first got the 213, the 204 needed some repairs which I didn't have time to do, and it sat on the drive for some time. Repairs got done and MOT passed, but still I was short of time, so still it sat there. A few months ago I found that water was getting into the cabin due to blocked drain by the windscreen wiper. I cleared this out and dried out the interior. The battery kept going flat (understandably), as it was often parked for weeks or months without being used. Each time I'd have to jump start it to get it going.

I am now trying to get it sold, however I have found some problems with the electrics. Most problems are encountered around the controls on the driver's door, but I suspect the problem might be more widespread. Any advice much appreciated! List of problems by location:

Driver's door

• Driver's window down works fine, but window up will only move in short bursts, and then only intermittently. Also, after a move up, it often shifts back down a bit (even when not at the top).
• All other door windows are unresponsive from this position.
• Folding mirrors will not open with unlock (they used to), and they almost always refuse to do it from the internal switch too.
• Mirror adjustments almost always refuse to work
• Power seat adjustment not working
• Central locking button not working. Externally from remote locking, the central locking on all other doors is perfect, but the driver's one only works sometimes (both lock and unlock).

Passenger door

• Mirror doesn't unfold on unlock.
• Electric window works fine
• Power seat adjustment works fine
• Central locking switch is OK. Door locks and unlocks fine.

Rear doors

• Doors lock and unlock fine
• Neither window works from the switches

Indicators

• Turning left - don't always get the tick inside the car. Externally they seem to all flash fine.
• Turning right - alternates between no tick/normal tick/fast tick. Lights are unreliable to flash and mirror light doesn't work.

Dashboard

• Upon starting the car, I get a beeping noise from the dash. I suspect this is something to do with park sensors, as turning those off (the light in the button flashes too) stops the noise
• The sport button also flashes. Setting car to Sport stops the flashing.
• On the instrument cluster, the lighting flashes on and off intermittently. It doesn't seem to matter what the headlight switch is set to, it still does it. The blue high beam warning lamp and the red handbrake lamp also flash. Externally the rear tail lamps and number plate lamp also come on intermittently - but the front lights don't.

At first I suspected the driver's door control module (as problems seemed to be centred around there) so I bought a used one on ebay. I fitted that and at first everything on that door was completely unresponsive, leading me to think it needed coding to the car. However today it's started working, although with same issues as the old one.

Next I suspected low voltage from the battery, due to it being flat before jump start, so I removed and trickle charged over night. Refitted and problems persist.

I'm now thinking I may have an issue with a SAM, but I'm not sure which one would cover the range of problems listed above. (Or could I have more than 1 faulty SAM?!)

Any suggestions as to what might be wrong, or where I should start with this? Many thanks in advance to anyone who can offer some help!

 

[Gbrowncls55]

I would suspect the battery. All sorts of "faults"can come up if the voltage drops.

 

[Swd80]

I would suspect the battery. All sorts of "faults"can come up if the voltage drops.

That was my thought too yesterday, so I put the battery on a trickle charger overnight. It was reporting 75% charged by lunchtime when I disconnected it but it had been at that at 9am too, so I presumed it wasn't going to go any further. (Perhaps I should have left it on longer?)
I've just tested it with a multimeter and it's reporting 12.87V - from what I've read this is a good result. The battery is Bosch S3 013 which is only about a year old, but it has obviously gone flat a couple of times.

 

[markjay]

That was my thought too yesterday, so I put the battery on a trickle charger overnight. It was reporting 75% charged by lunchtime when I disconnected it but it had been at that at 9am too, so I presumed it wasn't going to go any further. (Perhaps I should have left it on longer?)
I've just tested it with a multimeter and it's reporting 12.87V - from what I've read this is a good result. The battery is Bosch S3 013 which is only about a year old, but it has obviously gone flat a couple of times.

The Bosch battery will still be under warranty then.... go back to the retailer and get it replaced. They should be able to run a load test which will prove it's faulty.