Drivers Side Door Wont Lock Even With New Door Lock Switch

[SSSilverado23]

I have a 2006 Chevy Silverado and the Drivers Side door wont lock with the power locks. I bought a new switch for the locks and windows and its doing the exact same thing. All other doors lock and unlock just fine but the drivers side does nothing. There is a whining coming from the door lock actuator but it has always done that. Ive never heard a whine like that before though so maybe its the actuator?

 

I had replaced the actuator before but it still whined. Doesnt mean I could have gotten a bad part though. Its been a year and its not locking again. The problem last time was fixed with a used door and window switch. I thought that was the problem again so I bought new this time instead of going to my junk yard. Any help would be appreciated!

 

Corrie

[Doug_Scott]

I think you already know the answer. There are not many parts involved here, you have the switch, the wires, a relay or two, and an actuator. Take a test light, and check for power at the actuator when switch is moved. Also check for ground. Also, verify you can manually move the link the actuator moves to lock the door. If power is correct, and ground is good, and latch is not seized, then it pretty much leaves one part, the actuator.