Multiple Electrical Issues
Thread Starter
Newbie
Joined: Aug 2014
Posts: 11
Likes: 0
From: Columbus, OH
2009 C300 4Matic Luxury
Multiple Electrical Issues
It started with the driver's power seat quit working, so I checked all the fuses and they were fine and apparently it reset itself. Good. Then the next day the tail lights came on while sitting in the garage. I had the light switch in the auto position and turned them off, but the lights stayed on. Started the car and turned it off and the lights went out. Later that day I went on a quick half mile trip, parked the car back in the garage and 5 minutes later the radiator fan came on. Very loud. The car never warmed up. I started the car, looked for any service warnings, none, turned off the car and the fan stopped. The next morning tail lights on again. Started car and turned off car and the lights went out. Later I went to drive it and it was dead. No dash lights when I opened the door, put the key in, turned it, nothing. I then jump started it. I got the engine to run, but it would not drive. I move the lever into drive and engine running, and nothing. The car would not move. Again no service warnings on dash. 
Super Member
Joined: Oct 2014
Posts: 701
Likes: 103
From: Ontario, Canada
2009 C63 AMG, 2010 C250 4Matic Sport
I'd be interested to know if it's the full alternator that is failing, or just the voltage regulator module. I've heard of the regulator just being the issue rather than the whole alternator
