I have one in my truck, and I like it. It's better than climbing up in the bed to get tools out of the big tool box. The only downside is, it's wider than the wheel well, making it difficult to load plywood. I was going to get another one for the other side but didn't because I'm afraid that...
I am 99% sure you need the circuit board in the wiper motor Deere was talking about. It is a very common problem with those trucks. You can resolder the terminals mentioned above or replace the board itself. I think you can buy the boards aftermarket now. Check your local parts stores they...
Sometimes the plastic clip that holds the rod in the actuator wears out. Listen to see if the actuator is working in the door, but not unlocking. If you can hear the actuator clunk, but no movment from the lock you might check the clips inside the door.