Weird Electical Bug

[mnmasotto]

I have read every post dealing with the locking system. I did not find any similar to mine.

My central locking system seems to act on its own. The doors will spontaneously lock by themselves. I press the red button to unlock the doors but nothing happens. I am unable to unlock the doors manually. The round knobs seem to be temporarily frozen solid. Shut the car off and restart, the system works fine. Sometimes I will be working on the car (engine) and the doors spontaneously lock without the keys in the car! This problem spontaneously occured. No electrical work or elctrical devices were installed to precipitate this problem. Any help is much appreciated.

[cgarr]

Maybe you live in a bad neighborhood and your car knows it??

Seriously, Mine kind of does that too but does not lock it just makes a clicking sound like it wants to, when I open and close the door again it goes away. I am thinking its something in the door handle?

[Fast Corners]

The microswitches on the door locks can fail. A false signal from the micro switch can cause the doors to lock spontaneously. Do the dorrs tend to lock when the car is in motion or just when stationary? How does the system perform when using the key on either door?

I'm a bit confused as to why you can not unlock the dorr with the round knob. Turning that should overpower the electrical motor unless the motor is still recieving an impulse that keeps it energised.

If you have a friend with a carrera, I would ask to borrow his central locking relay. By swaping that piece out with one that works, you will be able to narrow down the cause.

Keep us posted.

[mnmasotto]

It happens all the time. I think the locking mechanism remains energized. I think that is why I am unable to unlock the door with the round knob. Again, this seams to be an intermittent problem. Where should I start?

[Fast Corners]

Where to start...That's a good question. It really depends on how good you are with electrical work. Playing around with jumpers and multi-testers is propbaly the quickest and easiest way to check out the system. Barring that I would do the following:

See if you can borrow the central door locking control unit from a fellow porschephile and swap it with yours. If your system works then you know it was that. I doubt that the control unit is at fault though.

The microswitches are my prime suspect. I have replaced a few over the years and once replaced, the locking system worked fine. Getting to the microswitches is a bit of a pain. They are on the lock portion of the door handle (inside the door). Thus to inspect them, you have to remove the interior paneling and then remove the door handle.

Since the Driver's side door lock is used far more than the passenger side, that would be the side I would start with. After you have the handle removed (microswitch still connected) you can actuate the lock with the key to verify the functionality of the microswitch.

[dshepp806]

Yes,..mentioned flakey switches will do this. Look at 'em/replace 'em.

Best,

Doyle