I have an 89 K1500 5.7 and the 4WD stopped working. I got a new actuator, not the problem. When I engaged the 4WD, had no volts at the actuator. I cut the actuator wire, put a voltmeter on the wire, then I have 12 volts. When I re connect the wire to the actuator, no volts. Makes no sense. I hooked the actuator directly to the battery with a toggle switch, and 4WD 's been working that way for 2 years now. I 'd like to fix it though. Any Ideas??

 

Hmmm that is weird.

 

theres a switch ontop of the transfercase. thats sounds like ur prob. iv had my switch go bad twice, there not that bad to change and not that expensive.

Hope this helps