here's the deal. I just bought this truck and the 4 wheel drive doesn't work. I'm pretty sure I have narrowed it down to the shift actuator. here is whats going on. the drive shaft turns when the truck is shifted into 4 wheel drive. I have 12 volts at my shift actuator and my grounds are good. I took the actuator out and installed a used junk yard actuator and it still doesn't work. I can put the truck in 4 wheel drive and watch the actuator and it does not move. how ever if I apply 12 volts and a ground manually from the battery it does come out slowly. Does anyone know any for sure way to test these actuators? Any ideas? Thanks.........more info... today I bought a new actuator and the 4 wheel drive is still not working. Does anyone know where I can get the 4 wheel drive schematics for this truck?