driver side door lock stopped working on 2008 Chevrolet Suburban 1500

fuses have been checked
arm rest unit has been checked

if you have power coming in and out of the switch then you will have to take the door panel off to check for power going to the plug at the actuator if you have power and ground then replace door lock actuator
I recently cleaned the car. Now for some reason, one of the back door actuators, only goes have way down when locking, there fore the door remains unlocked. I have to manually push it all the way down to lock it. When I am in the car and open the locks with the switch, they all go up and unlock all four doors. But when I pushed lock button, the passenger rear door only goes down half way.
What can be done? I already spent 250 dollars a piece about 50 thousand miles ago getting all four actuators replaced. I hate to spend another dime on it.