Door Lock Mechanism Malfunction (window springs back up) -What's Really Going On?
 

If you own one of these cars long enough, you'll eventually experience the common fault where the window drops when you pull the door handle, but springs back up before you get the door closed, usually causing the window glass to bounce off the the roof and the door doesn't close. There have been a few discussions here and there about what the technical failure is but eventually most say "screw it" and buy a $200 lock mechanism, which typically takes care of it.

I just had the 2nd one (driver's side) act up and when searching for the most economical new lock mechanism (don't get a used one - been there, done that), I found what appeared to be a nearly identical lock for a fraction on the cost on Amazon.com.

https://www.amazon.com/gp/product/B07KCY4BKV/ref=ppx_yo_dt_b_asin_title_o00_s01?ie=UTF8&psc=1

It's described for different models and years than my 986 but I thought it might work with some minor tweaks and parts exchanges. Turn's out it didn't lock/unlock with the key I ended work for the day in frustration.

The next day it was raining so I took some time to tinker on the old lock mechanism. I watched an excellent youtube video showing how to disassemble and clean a similar VW lock. https://www.youtube.com/watch?v=z5dtdyDDgrw&t=197s

I took apart the micro-switch which detects when the door latch is closed and found it was spotless inside and registered consistent electrical continuity when activated. What I did notice was that the switch nub was very low likely due to wear. I considered trying to build it up a bit, then I has a look at the cam surface that it rides on and found it deeply grooved corresponding to where the switch rides on it. This is why the switch fails: both surfaces are worn to the point that the switch can't be sufficiently actuated. A new lock mechanism is the only way to fix it.

In my case I removed the lock section of the new assembly and the micro-switch and exchanged them into my old lock. Presto! It works like new. http://986forum.com/forums/uploads02...1557085834.jpg
http://986forum.com/forums/uploads02...1557085865.jpg
http://986forum.com/forums/uploads02...1557085891.jpg

Great pics and description. I did get the cheaper Audi/VW door latch parts to work by just clipping off part of the red plastic. If it's not too hard to switch the lock section over, I like that solution better.
http://986forum.com/forums/uploads02...1557087124.jpg

Remove and replace the latch:

<iframe width="560" height="315" src="https://www.youtube.com/embed/FimZHn5QCD0" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>

Link to older discussion of the cheaper latches: http://986forum.com/forums/boxster-general-discussions/70183-vw-do-latch-actuator.html

Hey, that's great! I hadn't seen this discussion before but thought that others might want to check out some lower cost alternatives.

I don't mind paying full price for the right, high quality part but when a nearly identical part is selling for 1/10th the price, it's hard to ignore.