92 3/4 ton 4x4 not engaging

A buddy just bought a 92 3/4 ton 4x4 and the front end is not engaging in 4wheel drive. He says there is a two wire plug in coming to the diff that has power when the shifter is in 4 wheel drive and also a four wire
connector (with three wires in it) to the diff but no power to any of them. Any ideas?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

99% chance his CAD actuator crapped out. have him pull the actuator, (front of axle, above axle centerline) and push the plunger (in the axle) in with a wooden dowel and watch for the 4wd indicator to light up. if it does, your front axle is fine, replace the actuator as they fail quite often.
-Bret
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.