Inconsistent dead battery
 

Every few weeks, I find my 190 with a flat dead battery! I had the alternator and barttery checked and both appear to be fine. I can not get the cause of the mysterious dead battery. This is the same car that for no reason threw a straight baar code on the radio and the radio stopped working. Otherwise, the car runs beautifully. The steering seems to have excessive play in it. I was told to adjust to adjust the steering play on the top of the steering box and that the adjustor adjust up rather than down when the lock nut is open. Aany thoughts? My manual and tech book c=does not address these problems.
Thank you for your time and assistance.

You can check the voltage regulator brushes.
 

Just remove two screw from the back of the alternator and pull the voltage regulator out.
The radio will go into a "safe" mode if the battery is disconnected and the radio memory battery is low/dead.
How old is your battery?

Thanks for the input. we do not know how old the battery is...we have the car around 6 months and it had been perfectlly fine until this happened!!! We had the battery checked and we were told it was okay but if that is the problem, we would have no problem replacing the battery.... The car had been fine...until suddenly one morning when I went to work the lines were across the radio...a week later the other problem has surfaced with the dead battery...:rolleyes:

Check all your grounds.
 

Specially, around the strut tower.

? I am not sure what your answer means with 'strut tower'.

The electrical connections right in front of the battery!
 

They are connected to the car's metal portion (tower) where the top of the front struts (shocks) also attached.
Just follow the black wire and see where it connects. Also check the battery wires while you are there...

dead battery
 

Just went thru the same problem with my C230. Had the battery checked be 2 different places both told me it was ok. Went to my local parts guy and he told me the only wat to really check the battery was under heavy load. A lot of the testers don't put the battery under enough load. Went to my mechanic and he tested the battery and 1 cell was dead. New battery and zero problems. Original battery was 6 years old