4WD 4WD system

[SGriggs0]

I am not getting power at my front actuator, my transfer case control switch, or anything in between. I am unsure what it could be. Anyone have any ideas.

[Logan Lanfear]

Fuse would be the first check.  It might be a relay I cant remember off the top of my head.  

[SGriggs0]

I've checked the fuse and it's not blown. There is a switch in between the actuator (but not the actuator control switch) and the transfer case control switch on the top of the transfer case that had 0.2 V on it.

Edited September 11, 2019 by SGriggs0

[sk]

What year truck and is the 4WD actuator original?

 

GM used a thermal actuator on some of these trucks.  In later years (around '95 or '96) they were replaced with an electric one.  The thermal ones wear out and won't activate the 4WD.  It's easy to replace with the electric one.

[SGriggs0]

It's a '91. I'm not getting any power to the actuator. I'm thinking there might be a relay between the Instrument Panel and the transfer case control switch that is bad because I'm not getting power to any of my 4WD including the indicator lights in the floor shifter.

[riverbanks]

Power goes thru transfer case switch,brown wire to it,12v feed,blue wire leaving it,12v to actuator,chase your 12v supply, the brown one, broken somewhere