Well i was working on the benz this evening. we fixed whatever we had to fix and we disconnected battery and wanted to reset ECu like in other cars . Key position on and touh negative with positive cables for ten seconds. After that I cant start the car. I have all th elights but when i want to crank it cuts off like the battery is too weak. What might be the problem. Please help

 

Update: I managed to start the car but is weird. I turen on the lights and Ac with the ingnition on and the lights went Dim then something happened and the car got power it needed and started right up. Drove it turned it off ,started again.Later on same thing and now it keeps doing that. What might be the problme?

 

poblem solved. Batteru needed to be replaced

 

Did you make sure to install a vented battery of 1000 cca rating?
ohlord

 

I too am unable to start my car after a friend installed a new battery. I don't know what he did, but everything electrical still works but it won't turn over. The mercedes help line told me about using the key in the door, thenunlock and lock the car a few times to reset things, but no luck. When the key is in the dash andis turned to the 'engine running' position, all the warning lights light up and after a minute the airbag and check engine light turn off. Could this be an expensive repair? Maybe it'sa security issue? Please help!

Jeff

 

What year and model?Was the key out of the ignition when the battery was changed?
Have you checked the charge on the new battery?
ohlord