I have a 1993 500e that is having alarm problems. When I unlock the driver's side door, the central locking system works properly and unlocks all the doors, but the alarm doesn't disarm. When I open any door, the alarm goes off. I can get it to go off by going over to the passenger side and locking and unlocking.

Any ideas of where to look?

Thanks,

Barry

Assuming orig. factory alarm. There is a microswitch associated with ea. front door lock cylinder (and trunk). This arms/disarms the alarm. These are not available as a separate piece when I checked last and the whole deal has to be replaced if bad. They are suspect due to weather intrusion. There is a plug to the pigtails on this switch (gn.,yl.,br/bk wires last I saw one) that cracks at the wires insertion point and this can sometimes be repaired with a steady soldering hand.

The central locking system uses a separate swich on the actuator itself so this doesn't help the alarm any.

My bet is on a cracked green wire at the micoswitch plug.

__________________
The Golden Rule

1984 300SD (bought new, sold it in 1988, bought it back 13 yrs. later)

Thanks for the info, I'll give it a try.

Barry

Barry,
My '93 400E has exactly the same symptoms as your 500E and was wondering if you found the answer to the problem. I suspect the passenger door assembly but not sure yet. Another quirk it also does is LOWERS the windows when locking and RAISES them when unlocking. It appears to be out of phase somewhere or like the 'battery terminals reversed' which I know it can't be!
Thanks for your insight.

Tobias MB
400E