C200 1997 - Central locking/Electric Windows

[Andy Mcmanus]

Can anyone help?
Initially drivers window stopped working then front passenger window. Intermittent at first now doesn't work at all neither does passenger side rear. DRiver side rear does work but very slow.
Next problem the doors wouldn't unlock from the keyfob have to get in using manual key. Doors lock automatically using the internal button and once you drive.
Took car in the MB key fob checked and confirmed to be ok. Diagnostic check carried out system reset and initially ok but has subsequently failed. Diagnostic check stated faults with door control modules recommendation that three of the modules be replaced - not sure if I can put the price so i won't but as you can guess it is going to be costly. Before I take this route can anyone suggest where and what to start checking?
Look forward to receiving your thoughts.

 

[dogsbody]

c200 central locking/Electric Windows

I have had the same problem in the past with electric windows. Firstly found the windows would sort of operate when the engine was running and would not run when engine off... eg voltage was slightly higher.
Found that the problem was corroded earth points, causing high resistance resulting in the circuit so the motors could not pull enough current.
I would get a long piece of black wire attach directly to the negative pole on the battery and then directly earth the motors, and then try the switch... if the system works then you have an earthing problem due to corrosion..
Seems a bit silly to replace the modules, when it may be a bad earth..