I've posted on here many times trying to get help for my electric door lock problem on my 2000 f-150. Finally I found some help. Going to try these steps as soon as the rain lets up. Here is the url of the forum that I found with the help. I know I've read other people's problems on here so this should help out some of you.
http://www.f150online.com/forums/showthread.php?t=154123&highlight=failing+actuators

Ok, do the directions are good, but you're better off just buying new actuators. I pretty much demolished the driver's side actuator doing what these directions said. Ended up not being able to get the little motor apart to clean it. Not only that, but the hex screws holding the latch on were stripped, so I had drill them out and replace them. I ran into nothing but trouble with this. So, I put it all back together (the best I could with what I had left) and I'm just going to get new actuators. Anyway, good luck!