the drivers side lock usually locks/unlocks without a problem. but in order to make the passenger side door lock/unlock, i have to hit the switch back and forth, just to kind of bump it. guess it is time for a new motor?? or is maybe something binding up the linkage that runs from the motor to the lock. i have had to have pop-a-lock unlock my truck about 3 times. and everytime they have done it on the passenger side. maybe they bent the rod linkage?? open for suggestions

 

do a search for door lock actuator.....I bet you'll find your answer.

 

You can lube the assembly, it will help alot. My actuator was sticking on my Explorer. I lubed it and it still worked great for a year, then I sold it.