Interior light/Central locking help needed

[ezhik]

I could do with a bit of advice. Got an intermittent fault, the interior lights will sometimes slowly pulse on/off when driving and also when car stopped ignition off after exiting car. They do work properly otherwise. I'm also getting the alarm intermittently going off when locking, it will go off if I see the interior lights are pulsing when arming it, if the lights stay off it will be OK. If I re-open the drivers door and try again its usually OK on the second go. Also, if I leave it until the alarm goes off, even though the alarm has been triggered, Vag-Com has no fault codes for the C/L system or interior monitor.

I've sat in the car with Vag-com connected, it will show all doors closed, if I use the internal lock switch it will show all doors locked, yet intermittently the dome lights are pulsating on and off.

If I lock the car with the remote when sat inside (motion detector off!), Vag-Com shows all doors closed, locked and safe, yet again intermittently the dome lights will pulse and the alarm will trigger, but with no fault code to show what triggered it I'm unsure what to look for.

The unit under the passenger seat carpet is bone dry, never been wet by the looks of it.

I'm wondering if it might be something to do with drivers door, as a second go at closing will sometimes sort it out, but even so Vag-Com shows this door is operating correctly all the time, and I was thinking that if there was a dodgy microswitch here triggering the alarm it would also be reported as a fault code and give that as the reason the alarm was set off.

Anyone done work in this area and can offer any advice?

[ezhik]

Well I can answer my own question and give the solution if anyone else has similar symptoms. It was definitely the drivers door lock, I investigated it by using a screwdriver blade sideways on to fool the door lock into thinking (?), it was the striking plate, to see how the mechanism was working.

I could see that the bit of the lock that the strike plate pushed back was sluggish, then the penny dropped! Months ago, springtime, I had smeared a little copper grease on it, and now the cold weather had made it more sticky, and was holding back the lock from fully returning, well actually slowing it down enough to cause the problems I described. So all summer when it wasn't so cold all was working fine. Once the temperature dropped the problems started.

A clean up and a little WD40 did the trick, though a long the way I learnt a lot about the locking system on this car, and not to fiddle around unnecessarily in the future!

[passatmanuk]

Well I can answer my own question and give the solution if anyone else has similar symptoms. It was definitely the drivers door lock, I investigated it by using a screwdriver blade sideways on to fool the door lock into thinking (?), it was the striking plate, to see how the mechanism was working.

I could see that the bit of the lock that the strike plate pushed back was sluggish, then the penny dropped! Months ago, springtime, I had smeared a little copper grease on it, and now the cold weather had made it more sticky, and was holding back the lock from fully returning, well actually slowing it down enough to cause the problems I described. So all summer when it wasn't so cold all was working fine. Once the temperature dropped the problems started.

A clean up and a little WD40 did the trick, though a long the way I learnt a lot about the locking system on this car, and not to fiddle around unnecessarily in the future!

Hi, wd40 isnt the best thing to use as dust sticks to i and it becomes a paste and will wear parts down, hth
Brett