ok let me start by telling what happened. I started working on making the 4x4 work on my 1989 s10 blazer 4.3L. and I found that the actuator was not sucking, and I found that a vac line was broken. fixed that and now the actuator so sucking closed when engaged. I was out playing on a clay road dueing a storm. I went up a hill in 2 wheel drive and went to stop. I started slidding and then stopped on the down slope. put in reverse and didnt go anywhere. But did happen to slide it into a ditch. It dawned on me to try out the 4x4 and pull out of it. I engaged the 4x4 and the front tires did not move. I checked to make sure that the actuator was sucking closed and it was. I had my wife det in the driver seat and told her to put it in drive. when she pushed on the gas. I checked to see if the front drive shaft was turning and it was.

So what I know, is the driveshaft is turning and the actuator is sucking closed pulling the cable. Can anyone shed some light on this and let me know what it could be and why it is not engaging into 4wheel drive? Thanks all.

Vehicle info:
1989 S-10 Blazer 4x4
Automatic trans.
4.3 V6 Engine

 

You need to make sure that the actuator is actually engaging the front diff. Get one front wheel up in the air. Engage 4wd. Then pull on the actuator cable. If you can still turn the wheel that is off the ground, then your front diff is not engaging. Most likely cause is that the cable is stuck and not pulling all the way.