The vehicle: 1999 Audi A4 (B5) 1.8 Turbo Quattro
The problem: One day the driver’s front window refused to lower. Soon after the battery ran flat.
The diagnostic procedure completed:
1.) Removal of door panel to renew window regulator discovered driver’s front window motor VERY hot.
2.) Removing window motor – discovered motor is running continuously (to push window up even when all the way closed.
3.) I thought the motor had some sort of safety sensor that it would stop (or go back down) if a hand was caught… but this motor just pushes relentlessly.
4.) Inspection of relay (very confusing) determined lowest lieft green (think) once removed deactivated both driver and passenger window operation… so the motor then stopped. But this think is hard for me to tell if it is a relay or a heavy duty fuse. See photos




Summary:
Driver’s front window motor running continuously (even when all switches are disconnected!) Only removing relay / fuse stopped motor from running (up) all the time.
Unable to determine location of window relay?? (Anyone) it seems like relay is “stuck” in closed position because when disconnected from switch the motor still runs!
Suspect: dam central locking device (replaced the $1,000 sucker once when the sunroof drain tube clogged and flooded the rear trunk well killing the central locking device. So I will always have apprehension about the central locking unit.