Thought I'd share a recent experience. It might be of some help.
1991 Q45---Found the 10A fuse blown in the engine compartment that protects the interior lights & driver electric seat last night. Replaced the fuse today and it blew immediately. Disconnected the seat switches off the drivers door (actually all the plug in connectors were disconnected on the door panel) and it still blew the fuse.I then found there is a 75 amp breaker under hood, labeled "MAIN" that powers a control unit for both front power seats. (according to a 1994 FSM) With that breaker unplugged the 10A fuse no longer blows, but a friend had disconnected one of the driver seat motor connectors, so plugged that back in and the fuse still does not blow. To verify, plugged the 75 amp breaker back in and now the seat and lights all work normally with the 10 amp fuse not blowing.So, the short was either fixed or "upgraded" to an intermittent short. Oh boy, I dont know if that will be of help to anyone or not!
