is it the actuator? any idea of how much they cost to have replaced?

 

It is the actuator. I replaced mine a few months ago - it's a PIA having to work inside the frame of the door. I forget how much it cost ... I got it off ebay cheap.

 

I was gonna ask the same thing lol. Only it's my mom's 2000 Expedition, the driver rear door open 1 out of 20 times when you try to unlock it with the remote and the front passenger door is starting to act up. I guess I now know what to look for. Thanks for the info!!