Seeing as it was wonderful outside today, I figured I'd finally replace the front passenger door lock as it hasn't been locking properly for a while now. I ordered a $40 door lock module off ebay a few months back, seeing as how that was extremely cheap compared to what I saw in other places.
Well the whole job went smoothly, no issues as I've taken my door panels off several times prior (this was also a good opportunity to swap out any broken clips). About an hour after I started, I tightened the last screw and checked my achievement. Pulling the interior handle, I noticed that it was incredibly smooth, so much so that I worried that a gentle breeze might accidentally pull the handle. That should've been my first warning to stop, but I went ahead and closed the door to see how it works from the outside. Not bad, pulls very smooth and feels like a new car. I opened and closed the door twice and on my third try, the door wouldn't open.... :hmmm: Is it locked, I thought? Nope the little nipple is erect. I pulled up the handle to release the cable, thinking maybe I put too much tension on it but even so, nothing. Won't open from the inside or outside. This is when I started to panic a little because I just put a new interior in a few months ago and there was no way in hell I was going to be tearing it up already.
I took a break and by the time I came back I had enough energy where I thought I'd be able to just muscle it/punch it open. That didn't work so well... Finally, just as I was about to give up, I try to tug on it one last time and, as if a prayer had been answered, it magically opens.
I investigated what could have possibly went wrong but everything was hooked up correctly - there aren't many things that could go wrong here. Finally, my last resort was to just swap the old one back in and live with a door that I had to lock manually (for now). Looking at the new part, it turns out that the lever that holds the outside door handle cable was rubbing on something on the inside and sometimes getting stuck in the open position, simulating a situation where there wouldn't be enough slack.
Lesson learned: there's a reason that genuine VW parts cost more; they'll last much longer (at least longer than 3 pulls on the handle)