It is under the battery rack. Remove the battery and there are three bolts in the engine bay and one in the fender well.
look under the battery tray
We call it a horse dong, but to a partsman it would be a 4wd actuator and it is located in the front pumkin. There is a upgrade kit that can be purchased that will make it a manual engage and is generally cheaper than buying the actuator.
No, it is electric
on the front axel
Under your battery tray
It is screewed into the front Differential, towards passenger side but in the middle of the housing.
electric actuator (range selector)
that is a dealership only item
rear drivers side of tranny,likely a 700-r4 trans
It will either be the vacuum solenoid (actuator) located under the battery tray or the electronic solenoid on the front differential. Most commonly it is the vacuum solenoid (actuator). Once you take the battery and battery tray out you will see the rubber bladder of the vacuum solenoid (actuator) if it is torn or busted replace it. Check the vacuum solenoid (actuator) located under the battery and battery tray. It could also be the vacuum solenoid located on the firewall above the distributor (approx. 3"x1")
The vacuum line diagram on a 1985 Chevy Pickup can be found in the service manual. It details not only the location of each line, but its function as well.
The vacuum switch/actuator for the fan shutter is under the dash directly below the radio . IT is NOT easy to get to.