W211 Battery, electrical issue

[DaveW211]

Hi,

I've been lurking about PH from many years, but never had a need to post until now.

I've had my W211 E320 petrol for about a year, with no issues. Then a few weeks ago, the radio would turn on off its own accord when the car was off. This led to the battery draining. I went to jump start the car, and when I pulled back the boot carpet, it was covered in mould (I'd not stored anything wet in there). Once I'd jumped the car, there were more issues, hazards, radio won't work. One reverse light and one indicator stays on permanently.

Any bright ideas as to what this could be? The car's not really worth much and is just out of MOT, so I'm try to work out if it's worth investigating or if I just cut my losses and scrap it.

Any advice appreciated.

Thanks

[trevalvole]

One or two thoughts/vague recollections:

I'm guessing yours is a pre-facelift car with SBC and therefore two batteries? The initial issues may have to do with low voltage on one of the batteries.

A neighbour changed the battery on his W209 CLK and had to get a Merc specialist along with his Xentry diagnostics to get everything working again after it displayed similar symptoms to your car.

[DaveW211]

trevalvole said:

One or two thoughts/vague recollections:

I'm guessing yours is a pre-facelift car with SBC and therefore two batteries? The initial issues may have to do with low voltage on one of the batteries.

A neighbour changed the battery on his W209 CLK and had to get a Merc specialist along with his Xentry diagnostics to get everything working again after it displayed similar symptoms to your car.

Yes pre face-lift (2004), Didn't know about the 2nd battery, I'll have a look, thanks for the reply.

[TarquinMX5]

Mould in the boot? If it's damp, the seals could be leaking around/onto the rear light unit causing short circuits; it might be the light unit seal or boot seal.

[Panamax]

DaveW211 said:

Yes pre face-lift (2004), Didn't know about the 2nd battery, I'll have a look, thanks for the reply.

A handy link here,
https://www.youtube.com/watch?v=6l20UMf3oT8

[Greenmantle]

google
w211 alternator voltage regulator
£60 genuine part.
These are standard wearable parts.
Your batteries are not recharging so the classic shutdown of auxiliary units takes place.

[DaveW211]

Thanks for all the replies, I'll take a look.