Power door lock problems - '82 528e

I recently purchased a 1982 528e, and the power door locks seemed to work okay at first. Now, however, whenever you lock the trunk or driver's side door, all of the door locks engage (which they should), but then immediately disengage. This is maddening, because I can't lock my car! :eek:

I'm suspecting the driver's door mechanism, since while it seemed to work at first, I do believe that it didn't always lock all the doors when I pushed down the driver's door lock. Now it does lock them all, but then they immediately unlock. I've also seen that there is a central locking computer, and a vacuum system involved.

I was wondering if anyone has had a similar problem, and could point me in the right direction before I go blindly taking things apart :confused:

Thanks,
Scott

:o one thing you can try is clean your
fuses and replace the one that controls your
gauges and others . It worked on my e28 528e
If not try taking the drivers door off and make sure
that the lock mechanisum(?) locks all the way and
doesnt stick . Thats what i know . hope it helps

Yes, the drivers door central locking unit has some extra switches on it, which is how the module knows that locking is complete.
It also helps to prevent you locking the keys in the car.
If the "full lock" switch does not operate, the system unlocks.

Check the passenger door too. I think some of these have a "locked" switch but not an "unlocked" switch.

If everything seems in order, check the multiplug from the door to the front "A-Pillar". Part of the connector may be water damaged. Ensure the rubber boot is fitted correctly over the plug to prevent water getting in.