99 E320 Power Seats and Windows
 

My power seats and front windows quit working from time to time when the car parked. I can disconnect the battery for a second and they will start working again. They might work for a day or a week and always start working when the battery is disconnected.

One garage said it was the convenience relay...another says it’s a computer located in the door. I don't have a lot of confidence in either recommendation...any advice?

I believe that you have a computer in each rear door on that car, and the "convenience relay" must be the SAM, which is somewhat expensive. Since they all go out, I'd not think that this was the door modules.

I've never heard of this problem, so I'm sorry that I can't be of more help.

Have you tried reprogramming with the key when this occurs rather than disconnecting the battery?

The procedure is in the manual.

Well don't keep disconnecting the battery as that can cause damage as well!

Most likely problem is one of the rear door control modules. Have a trusted shop check out the interior network of computers.