'89 MBZ 300SE rear door locks refuse to lock automatically on 1990 Mercedes-Benz 300SE

My wife's '89 MBZ 300SE rear door locks refuse to lock automatically when she locks the driver's door with her key. When she opens a rear door while the front doors are locked the alarm goes off. When she locks the rear doors manually, they stay locked. When she opens the driver's door with her key the rear door locks open automatically. Whar needs to be fixed?

by in Las Vegas, NV on February 02, 2011
1 answer
ANSWER by on February 09, 2011
Well my 91 560 sel was doing the same thing bcuz we started messing with the radio system, the only thing i did for the alarm problem was take every fuse off 1 by 1 until the alarm shut off, so dats all i can help u with. It was fuse# 15 on mine. Note: the automatic door locking system wont work with out it so just try that or keep hearing that anoying alarm... Good luck