I do not know where it is on the first gens, but I have a second gen '95 that keeps the actuator motor under the battery tray on the passenger side. It's bolted onto the front of the fender well and easy to get to once you remove the battery and tray. When transitioning to 4x4 modes, you can shift the transfer case on the fly to 4-hi, but take your foot off the gas. I will roll the truck, yank on the center console shifter knob and keep my foot off the gas. Within 3 seconds she locks in with a light click and the 4x4 light on the little diagram lights up. Then I stomp the gas and go.
