Ur quattro MB Central Locking

[Benjamino]

Hi All,

If anyone can shed any light on what might be wrong with my central locking and why it suddenly stopped working I'd be eternally grateful....

As you probably know, the ur central locking only actuates from the driver's door and only locks and unlocks the doors. It just stopped working one day, whether this is coincidence or not I don't know, but it seemed to occur when my impatient 5 year old daughter tried opening the door whilst I was unlocking the car via the driver's door, but before the passenger door had chance to unlock!!

Where do I start... behind the driver's door card, behind the passenger door card or in the boot where the pump and vacuum tank are?

Thanks in advance

[Isimmo]

First of all you need to know if the pump runs when you activate the door, that'll tell you broadly speaking whether it is an electrical issue or a vacuum issue.

Hope this helps, report back with your findings
VBR
Ian

[Benjamino]

Thanks Ian, I can't hear the pump when turning the key as I used to... does this indicate anything further at all?

Cheers

[Isimmo]

At least you won't be chasing vacuum leaks!

I suspect it's the contacts in the door switch, but below is the schematic for a 1987 US spec Ur/GT etc.



You might find additional wiring from an alarm around the switch, and don't forget to check and clean the fuse first, just in case.

[EA262]

This might help.
http://audi.humanspeakers.com/power-locks-85.htm

[lefthooker]

Never quite understood the need for central locking on the two door coupes and quattros, not as though it's much of a stretch to lock or unlock the passenger door is it?

[Hanuman]

I never understood the need to fit a pump with lock sensing on only one lock, having decided to fit central locking in the first place. Either make it work completely, or don't bother.

Worth thinking about how it works-(and bear with me, as it's been a while since I played with this, so I'm going to take look at the diagrams when I get a chance)

The key lock is turned, which pushes the rod down in the actuator with the sensor. This makes/breaks the contacts, which signal the pump to run. The pump then sucks or blows, and actuators are forced open or closed.

The rods are linked via a small quadrant on the rear of the lock. Unlike other models, where there is a clamp securing the rods in the assembly, in the UR, I think they are either pushed in (metal rod has a ball on top, quadrant is nylon/plastic.) or require inserting with a quarter turn.

I once investigated the lack of central locking on my ur, to find that one rod was completely missing foollowing a visit to a body shop for repairs to the door.