I see a lot of power lock issues, but not the one I'm having. '99 GT 'Vert, bought it new. Door locks work fine from inside buttons and remote - EXCEPT: lately, if I toggle it quickly (lock, unlock, lock, unlock ...) they quit working after 3 or 4 cycles - they click, but the mechanical button on the top of the door stops moving completely and they stay locked or unlocked. Usually the driver's door quits one cycle sooner than the passenger door. Same results with the remote or inside buttons - either remote, either door button. If I wait a minute, they are fine again, until I flip them rapidly. If I wait only a few seconds, they work once or twice. Key locks work fine. I don't remember this happening in the past, but likely didn't try this often. What can do that? Does anyone know if the actuator is purely electrical? It almost acts like a vacuum actuator running out of vacuum - except they come back after a minute, engine running or not. Could this be electromagnetic actuators overheating and getting sticky until they cool? Any ideas at all?

 

...could be. Why do you feel the need to rapidly cycle your door locks. They were not designed for that.