The AD door locks can mess up and go into lock mode when you shut the door. I believe there is a discussion about this in the shop manual and it claims the an improper adjustment can lead to this. I have had it happen. If this happens to the driver's door and the passenger's door is locked from inside, the key will not unlock it.


1951 GMC 1 Ton Flatbed -- It is finally on the road and what a great time I have driving it!
1951 1 Ton Completed


My Chevy Master 4 Door is on the Road!