Can You Help with a Door Locking Problem?

[mountainbiker]

I have a 1997 Ford Explorer Sport.

Background
When purchase, it immediately had a DEI Viper alarm system installed. The alarm system has a module in the driver's door which is interfaced to the doors and windows to allow it to unlock/lock and roll up/down. The vehicle has had its doors locked and unlocked by the Viper remote for almost all of its life. (As a side note the key locks are now extremely difficult to use after 10 years of no use.)

Problem
The driver-side door will not remotely unlock/lock.

Details
- Using the Viper fob, the remote will unlock/lock all doors but driver's.
- Using the OEM fob, the remote will unlock/lock all doors but driver's.
- The driver-side door can be manually unlocked inside by using the door handle.
- The driver-side door can be manually locked inside by depressing the "plunger".
- The driver-side door can be manually unlocked/locked outside using the key.
- The driver-side keyless entry does not unlock/lock the doors; however, the first depression of the number pad does light the interior and after all number are entered you hear a click/relay from that module on the left side cargo area.
- I have removed the Viper module completely out of the door, and all the above details are the same except the first.

Can you help diagnose?
Could it be an electonic OEM unlock/lock module or actuator which isn't working? Also, what do you recommend for getting the door locks working a bit more smoothly, so I can use the key until the problem is resolved.

 

[sapacif]

You have described my situation in this thread. However, I have not found it to be a problem. In my case, this situation did not occur until after I had maintenance on the driver's lock to replace the electric mechanism and the lock itself which had frozen and was unusable.