My car a weird problem with the power locks its 99 TLand I can't seem to figure out, when i hit the lock/unlock switch, the drivers side front and back locks work perfectly, the front passenger will work once in a while and the rear passenger never works. I already checked fuses, the plug to the solenoid and everything's looks fine, any suggestions? I would highly appreciated it, thank you

 

Welcome to AZine.

Sounds like actuator motor. Cheap 'n easy fix.

Take them out, and test them first.

 

^^^^^

Agree. Very likely one intermittent actuator, and one bad actuator.