I have a 1996 a4 2.8 quattro with 107k miles and the button to lock all the doors on the drivers door no longer works. I took off the doors and everything looks okay physically. Its not a fuse either. Any ideas on the problem? solution?

 

Do you have remote locking installed on your car? Also just because everything looks ok, doesnt mean the switch is still good. I would try ordering one from a junk yard for cheap to see if it fixes it.

 

Can you lock the doors remotely?
Do you have a voltmeter to check if the switch works?
Have you tried some contact clearner?

 

I bought the car used and it comes stock with remote locking but they didn't have the remote any more. I will try the voltometer and contact cleaner, thanks.

 

you can pick up a used remote from ebay.