decampos

I have searched the forum but haven't found an answer to this specific issue.

When locking the doors (from either door, using either the key or the button or ****), the actuators lock the doors then unlock them.

Is this a known problem? The locks have always been pretty noisy. Maybe they were dying and now they're dead?

Any help very much appreciated.

Nicole

my first 928 did something like this when I used the passenger side lock. It required an adjustment on the driver side electric lock motor.

decampos

Hi Nicole. Thanks for your reply. Do you know what kind of adjustment?

Alan

Generally the way this works is the initiating door lock - the one you change the state on (say with the key) - causes the other door to follow it to the same state. But there is only a limited amount of time allowed for that to happen - if the other door doesn't get to the same state quickly enough due to binding up, excess slackness in the linkages (or whatever) then the initiating door will instead change it's state back. The early cars essentially have a motor driven lock mechanism, while the later cars have a solenoid (faster) system - early cars are more susceptible to this cycling issue - in some cases they can be off just enough that they continue to cycle (lock-unlock-lock-unlock...).

Figure out which lock has the most resistance (from the key/lock ****) or seems to change state the slowest and focus there. Sometimes it's as simple as the plate under the inside lock **** being screwed on too tight... Other times you have to get into the door.

Alan

decampos

Thanks for your reply Alan. Interesting insight to into how the locks lock (or don't lock). It seems that only one side does the cycling (whichever side has had the key turn, button pushed, **** turned). The mechanisms have always had a really horrible grinding noise which I guess was a sure sign that they were not long for this world.

For the time being, I've removed the two inline fuses. Can only lock/unlock one door at a time but it does it in glorious silence. I might keep it that way.

riziuebru

Thanks for your reply. Do you know what kind of adjustment?

Tom in Austin

As Alan said, the plate under the inside lock **** being screwed on too tight is a good thing to check. Only a real 928er would realize that makes a difference!

Alan

So it seems you are now saying that really only the side you lock from cycles state back to what it was - other doesn't move at all - is that the case? Does this happen for both unlocked -> locked ->unlocked and locked ->unlocked -> locked also? Does it always happen or does it sometimes work correctly. Same from both doors?

What is the state of the other lock wrt the starting position of the lock that cycles (same or opposite).

Alan

decampos

Yes, that is the case: both doors make the grinding noise but only the one door whose key is turned/button pressed/**** turned actually locks (then unlocks).

I thought originally that both doors were locking (then unlocking), but it's only one.

It no longer works correctly at all. The state is always unlocked. That is until I removed the two inline fuses.

Thanks again for your help guys though I currently have little motivation in fixing it as I quite like the simplicity and silence of the current 'manual' set up. It is something that I may get round to looking into if I need to ever remove the door panels for a different job (speakers may need replacing).

Alan

I think one of the switching wires is grounded permanently - e.g. shorted to the chassis somewhere

There are 2 wires that run between the locks - they act like a traveller pair for a 2 way/ 3 way switch (think 110v lighting circuits). These are Yellow & Green/Black wires,

Here is an experiment: (since you said you cannot lock the doors with central locking active) - remove the fuses lock both doors. Put just one fuse back in (red/black & red/white wires). Does the driver's door unlock? remove that fuse, lock both doors, put one fuse back in (red/black & red/black wire) does the passenger's door unlock?

Alan