electric windows on 97 e class
 

Sending me crazy this one, electric front windows on 97 e class 300td. They work intermittantly, I have renoved both block connectors on the n/s o/s foot well, hard soldered and heat shrinked each wire in turn, no luck.
If I leave the battery to go dead flat then they will both work for a while then stop
I've checked fuses, looms, connectors etc.
Mercedes dealer in Derby want £1,000 to CHECK what it is.
Does anyone have any ideas:confused:

Does you car have a "smart key"?? If so then you most likely have a network issue with the interior bus.

Sorry for asking a daft question, its a triangular black key with 3 buttons on it, does this help?