I am not sure what the actuator is but last weekend I went up to the mountains to play in the snow. I used my 4wd and by the end of the weekend it was acting up. When I start my truck, sometimes it will be in 4 low or hi or the little red light will be on and it always says service 4wd. If its in 4 low or hi I have to turn the truck off and then back on and hope it has shifted out. I have the Z71 model. Any help or suggestions would be appreciated. Thanks

 

Replace the switch, that seems to be a common problem with 99-06 z71 trucks