Right so now, if like me, you have found 1 of the 3 micro switches is stuffed (technical term) its time to replace it.
More often than not I have found out that it is the door latch switch that is the problem (one with the wires).
The above is a link with part numbers (at the bottom, ignore the ebay one) for a replacement switch.
RS components stock number 4728162 (http://australia.rs-online.com)
You will have to cut the wire's on the failed switch and solder them onto the new one then mount it and use hot glue to hold it in place. You want to use the NO contact and COM for the switch, but as always test once done before closing the door. At this stage this is the best option as it looks like the original switches are either discontinued or, and more likely, they can not be purchased by the general public. But hey for a couple of $$ plus free postage its worth a shot.*
I have a few of these so send me a PM if you need any.
The second type of micro switch can be see in this pic. There are two, one with left hand pins and the other with right hand pins.
*replacement switch still being sourced for these I will update once i have one*
It looks to be a Cherry DK series switch, DK1G-TRA0 for the RH pins and DK1G-ULA0 for the lh pins. These however do not seem to be available to the general public
When looking at the photo the one furthermost away from the motors is to monitor the status of the "dead bolt" lock and the one closest the normal lock.
Looking at this photo you can see how it all sits together. The silver motor on the right is the "dead bolt" motor which basically moves the white plastic underneath the circuit board into position so as the normal lock cant be moved. The white piece on top moves with it activating the micro switch.
The motor on the left with the black band is the one that actually locks the door. As the slide moves it contacts the switch. This movement flicks a lever on the out side that moves the locking lever in the mechanical set up.
Any questions please PM me for fastest response. Any members in WA I'm more than happy to help a little or a lot and if anyone else wants me to test there unit then I am happy to if you want to send them to me. Keep in mind you wont have a door lock for a week or so either.
As a side note any passat owners that have the same problem look here:
or MKIV owners:
The MKIV one has photos of the dry/cracked solder joins if you wish to know what to look for.
As with all DIY's i take no responsibility and its up to you to make sure you are happy to do it and check all part numbers are correct.
*all pricing correct at time of writing and i take no responsibility if it changes.