Electrical Issues

[Vinney222]

Hi,
I recently purchased a 2002 W211 E240 Elegance. I decided to get it serviced and ready for winter, so I took it to my local garage I've used for a while. They did a full service, plus changed the brake fluid, anti-freeze etc plus sorted out a couple of oil leaks. I was getting an error message occasionally on the dash saying "electrical consumers switched off" which, after a plug in test, was put down to a weak battery which they changed. Got the car back yesterday and no error messages, great. But then this morning I noticed my heater blower motor wasn't working and the A/C switch on the dash showed it switched off but not able to turn it back on. I know they were working fine before I took the car in. The garage has the car back, but I can't get it out of my mind so I did a search to try and find any possible answers. I did come accross an article that said, if the battery is removed then certain systems need to be reset or "faults" can occur. Could my malfunctioning blowers be affected by one of the batteries being changed?
Any suggestions would be great.
Thanks

 

[toolman1954]

I am thinking you should have 2 batteries on your car, what is the state of play of the small one under the air con air filter. Did they check that. Although that would not affect the air con not turning on. Perhaps they have disturbed a fuse that controls these items.
Items needing resetting are generally the windows and the steering, which they must have done.

Steve

 

[Vinney222]

The garage said they checked both batteries and it was the one in the boot that was changed. To be honest I never checked the windows. It was 05.30 when I drove to work and a bit too chilly to open them. I have read that even with the ignition switched off but the key left inserted, can cause problems with something called a SAM unit? Trouble is, I don't want to make any assumptions about what might have happened, but I cant help wondering if I should have gone to MB for the work and not my local garage?
Dave

 

[markjay]

I think there's a reset procedure for the aircon (similar to the electric windows) that needs to be done after battery change.

 

[CowleyStJames]

Just a thought, were you sure the garage didn't short the battery out damaging a sam controlling air con?

 

[Vinney222]

That I don't know. I spoke to them today and they told me that the blower motor is faulty. It will be replaced in the morning. Only then will I know if the air con problem is linked to the faulty blowers or is possibly another fault.

 

[Vinney222]

My car came back today after having a new blower motor fitted. That part at least is good. However the switch on the heater control panel that is labelled AC Off and has a small red light, is still lit up. This presumably means the AC is switched off? I cannot get this light to go out.

 

[Codger49]

For a 2002 car, the A/C off being illuminated does mean the a/c is off. In 2005, MB changed to the red light meaning a/c is on, in line with just about all other manufacturers.

Suspect you should seek out a recognised MB indy to look at your car. Depending on the model of a/c fitted, its control panel can provide diagnostic information, or if not, Star diagnostics would identify the actual problem when used by an experienced mechanic.