Central locking issue

[John Blount 11]

Can someone give me an idea what might be faulty with this one??

 

Just had an alarm fitted today (Sigma SG30) before this the cars never had an alarm before only the standard central locking with the key no alarm at all. This alarm like most when armed with the key fob will automatically lock the doors hence the key is not needed to lock the car.

 

The auto electrician who fitted it today has told me he thinks the drivers door lock mechanism is faulty as when armed with the Sigma key fob the passenger and boot lock but the drivers door doesn't and after a few seconds the central locking activates again as it thinks the drivers doors not closed!

 

I wouldn't have noticed originally using the key in the drivers door as I'm manually locking it but now the alarms doing it the 'Peg' in the door card to manually un-lock the doors doesn't even attempt to move like the passenger one does.

 

Any one have any ideas if it is the mechanisim at fault and if so are we talking about the mechanism under the plastic cover that locks around the catch holding the door closed or is it one inside the actual door itself??

 

Any help would be appreciated:thumbleft:

[Will.I.Dub 11]

The factory central locking is triggered by two 'methods'.

a. Turning the key in the lock triggers the microswitch in the door handle which activates c/locking

b. Pushing down a lock 'peg' triggers the c/locking module in the door which in turn triggers the locking/unlocking.

 

Have you a Bentley manual? There is a comprehensive diagnostic procedure which covers c/locking in it.

 

Is the Sigma activating the factory c/locking electrically or mechanically?

[John Blount 11]

I've now got hold of a Bentley manual.. thanks for the advice..

 

I've a theory after remembering a couple of things. When I brought the car the central locking pump had packed up and a local VW specialist replaced it with one I got for them, I vaguely remember him saying he found an air leak which he sorted but only lock the car using the drivers door.

 

Here's my theory: I have always used the drivers door to lock the car thereby manually locking that door of which doing so the micro switches in the door handle command the central locking pump to run and lock the rest of he car. As I never used any other door to unlock or lock the car I would never have noticed the problem.

 

Now the alarm locks the car this has caused an issue as the key isn't being used in the drivers door and isn't being locked manually. When the central locking pump is commanded to run it locks all the other doors and filler cap but presuming a component (vacuum/air wise) has been disconnected it has no way of locking the drivers door.

 

I think the actuator or vacuum tube etc in the drivers door is leaking air which caused the central locking pump to run constantly which is why it packed up and I needed to get another. I bet they fitted the new pump and that ran constantly of which they got it down to the drivers door and disconnected and blocked the vacuum tube so the rest of the system operated.

 

Does this sound plausible to anyone who's had a simalar issue?