Porsche Enthusiasts Club Forum

Went out for a test drive in my 928 today to test out the new RMB that I put on it last night. When I parked up and got out to lock it the central locking did its normal whirring and then carried on whirring and unlocked itself again??? OMG! Has done this once before but I can lock via the key in the passenger door which locks the car OK. However this time the passenger door does the same???

Any idea's what this may be and how to fix it? Has anyone else had the same problem?

I don't have any separate alarm or key fob so its just working on the Key in the doors. This key does seem to be the "short" key and I have 2 short keys and no "Long one", but it has locked normally over the last 3 months or so with only the odd hick-up. But now it seems to be a constant problem.

Any help would be appreciated

Steve

Electrics are funny things, but I've had a similar problem to you before where the doors were trying to lock all the time. This meant it activated the system that closes all the windows if you hold the key in the "lock" position. This meant the battery would go flat in like an hour as the motors burned off all of the charge in the battery.

I found it to be a faulty boot electrical pickup on the key lock. The inside of all the locks has two contacts to either side and a paddle like extrusion in the middle that the key joins to when you put the key in the door.

As you turn the key the paddle rotates left or right and makes a circuit with either of the contacts, and locks/unlocks the doors. If these contacts get dirty they can start shorting and all sorts and cause all sorts of weird symptoms such as yours.

My guess would be to disconnect each door lock in turn until you find the symptoms disappear. I'm not familiar with how they connect electrically within the door, but in the boot I had a very simple 2 pin plug that once I separated the alarm returned to normal operation.

I'd suggest seeing if anyone on here knows more about how they connect (or having a look inside one of the doors yourself), and eliminating each one in turn until you find your problem.

Hope this is clear!

Sam

Will look at the boot lock. Maybe I will have to remove the door cards too and check each door lock too.
I have no remote alarm to upsett things so just down to the door locks themselves.

Cheers
Steve

I cleaned out the boot lock etc when i was aligning the boot release, however mine had a 20p piece wedged in it, so its entirely possible that something has stuck in it and is stopping it working correctly.

Hi,
I had a similar problem recently and had to replace the drivers side lock barrel that had worn out, which is quite a fiddly job. If you take the door card off there is a pair of wires that run along the top of the door just under the window with an connecter halfway, try disconnecting this and locking the other door to see if it will stay locked, if not then try the same on the passenger side, although the drivers side is obviously more likely to be the worn one.
Good luck
Jon

Latest Update:-
Didn't get chance to remove the door cards at the weekend, but did manage to confirm which lock is causing problems. I blew the C/Locking fuse for the button in the centre console, so having replaced that I tried to lock the doors from the Centre Console button. Passenger door sort of locked..and if I pushed it again it locked completely. I could then get out of the drivers door and lock this door with the key! Hey presto all locked up safe car!

I unlocked it by the key and tried to lock it again from the outside and they wouldn't lock again. So pressed the central locking button again and passenger door locked again...althought sluggish..... and managed to lock the drivers door again with the key. So, my guess is that the passenger door is the one I need to fix first and then see where I go from there.

Tried to find the door fuses behind the fuse board, found one...removed it but that only affected the drivers door....can't find the other fuse at all????? Amazing how things disappear.

Will keep you updated.

Steve

Removed both internal door lock dials and the surrounds - sprayed some WD40 in them and worked both of them for a while. They are both a lot free-er but still the C/locking doesn't work!

I can now convincingly use the central console button to lock the passenger door and then get out and lock my drivers door and the car will lock that way. But any other way and its all messed up!

I guess I need to remove the Passenger door card next to try to rectify this. However, I am not sure when I will get time. I have tried again to find the passenger side 400ma fuse behind the Fuse board but can't find the damn thing anywhere? Can see the Drivers door fuse but not the passenger door fuse. Bugger!