CLK280 battery drain

[Martin Johnson]

Can anyone please advise? I have a 2007 CLK280 Cabriolet. Recently the battery has drained overnight. The navigation screen is frozen, the radio has on occasion switched itself off and the information screen in the instrument cluster does not show any nav or radio detail. The volume control on the steering wheel no longer works. Looking at various posts on the internet, the most likely faults appear to be the alarm siren, the audio gateway or the memory seats.
Has anyone experienced similar problems before?

 

[Steve@Avantgarde]

I would start by firstly, charging the battery off the car, and that should allow a full shut down of the car whilst the battery is disconnected. Then check the fault codes, looks like you have lost the CAN for the interior network.

You didn't jump start the car by per chance when the battery went flat did you?

 

[Martin Johnson]

I would start by firstly, charging the battery off the car, and that should allow a full shut down of the car whilst the battery is disconnected. Then check the fault codes, looks like you have lost the CAN for the interior network.

You didn't jump start the car by per chance when the battery went flat did you?

Yes I did - the car was on the road away from home

 

[Martin Johnson]

Yes I did - the car was on the road away from home

 

[Steve@Avantgarde]

High chance you may have spiked something then. You can't jump start MB cars, they have limited surge protection. 18v from an alternator on another car is dangerous territory.

Sure you didn't reverse polarity it as well?

 

[Martin Johnson]

High chance you may have spiked something then. You can't jump start MB cars, they have limited surge protection. 18v from an alternator on another car is dangerous territory.

Sure you didn't reverse polarity it as well?

No I was careful not to do so

 

[Steve@Avantgarde]

I would check you haven't melted the K40 relay, which is the box that has the battery + charge point in.

 

[Martin Johnson]

Thanks for your help. I have the car booked into a trusted MB independent tomorrow. Hopeythey will resolve the issue

 

[John Laidlaw]

Good luck Martin should be a relatively pain free fix