The is a hatch lock from a 90 S4. This lock has 2 problems.

1. The key will open the hatch but it will not turn in the other direction. So, it will not lock the doors or arm the alarm.

2. If the alarm is armed and you open the hatch, the alarm sounds. So, it is not defeating the alarm as it should.

The same key works properly in the ignition and driver door lock. However, it also will not turn in the direction to lock the door and arm the alarm in the passenger door lock.

Is problem 1 a mechanical problem with the key or the lock? Since the passenger door lock is similarly affected (although opening does not sound the alarm), I'm not sure.

Is problem 2 electrical or mechanical?

How should I proceed to deal with this?

 

Bill, I am interested in this topic because I have the same issue. Only difference with mine is that the rear hatch lock was swapped at some point and uses a different key than the doors and ignition.

Matt

 

Matt:

I have rekeyed a gas cap lock by disassembling, swapping a few of the blades and filing down another couple until the same key worked it. This lock looks a bit harder to disassemble, but you could "key" it to use the same key if you can get it apart.

Why it only turns in one direction puzzles me.

 

Bill.............given that you use the same key for all 4 locks is it always oriented the same way?

If the drivers door and ignition work as they should with the same key regardless of orientation the problem with the passenger door and hatch are likely mechanical issues of the respective locks.

Can't imagine an electrical issue preventing the key from turning.

 

Malcolm:

Sounds reaonable for problem 1.

Problem 2 appears electrical - I just removed up the electrical part of the lock and the contacts were corroded and full of dirt.

 

A fine mess.

Of course the key tumblers are fine. Something else is blocking it from turning counterclockwise.

I've read the Oz guide to rekeying, but it says nothing about the spring that fell out.
http://www.928.org.uk/mambo/content/view/56/59/

The electrical contacts were so corroded, a replacement lock is the only likely solution.

 

Verdict: Something is broken in the alarm portion of the lock preventing it from turning counterclockwise. I opened it up, but it just a mess in there. Wonder what I am going to find in the door lock?

 

I figured out the problem with the hatch and passenger door lock...details to follow under "The Anatomy of a Hatch Alarm Lock"

 

Here they are:
https://rennlist.com/forums/928-forum/380616-the-anatomy-of-a-hatch-alarm-lock.html

 

your fac. alarm works?? wow! mine doesn't interfere w/the operation of the car, I thought that was a major accomplishment....