Power locks problem on a 2000

So I just bought a 2000 f150 and its had this problem with the locks since before I bought it. When trying to use the power locks, it tries to work but acts like its not getting enough power to push or pull the lock. I can hear it trying to work, I haven't had much of an opportunity to look into it since its been pretty dang cold outside.
Does anyone have an idea of what my problem could be?

 

either the switch or the actuator

 

ive had to replace both actuators the rear door lock cables and latches both motors for the power windows its a nightmare

 

^^what he said

 

yeah what he said, I had to replace one of mine and local shop only charged 50 bucks I think

 

New here also, does anyone have pics or is there a post showing the replacement of the lock mechanism? My passenger side works on mine but the drivers side does not, can't even hear clicks or anything, so i'm thinking the actuator is dead.

 

thanks guys, thats what i thought the problem was. but thought id throw it out there and see what yall thought.

 

Found this replacement post...not a whole lot of info but enough to help I think. I'll be using this and other posts to fix my drivers door lock.
http://www.f150forum.com/f6/door-lock-issue-71358/

 

thanks