I have a 84 S10 blazer 4 x 4 with a 2.8 and 5 speed manual transmission. Finally got the beast running after motor swap now I have a 4 x 4 issue. Put it up on jack stands and when I put it in 4 low or high the front wheels don't spin. If I put it in neutral on the shift selector it does disengage everything. I don't get any lights on shift selector. I have both electrical plugs plugged into selector switch at shift lever. The shifter switch looks like the guts are missing. I can't find a picture of one anywhere or any wiring diagrams for it. I noticed that when I start motor and watch the vaccum actuator that it pulls in if I disconnect the vaccum line it releases. I see where the cable attaches to front axles and there are two wires (black and a yellow one) that hook to it also. What are they for? Also there is another hose on the back of transfer case hanging down which I have no idea where it connects?

 

If the actuator is pulling the cable, then the t-case is going into 4wd, and the vacuum switch is working. Now the next thing is to turn one of the front wheels when you have it running in gear with all 4 wheels off the ground sometimes it needs to be moved a little to engauge the sleeve in the front diff. If it doesn't engauge then you have a problem with the cable, the clip that retains the cable on the sleeve (inside the front diff) or an internal front diff problem like an output shaft failure. The extra hose on the t-case is probably the vent, and it needs to be as high up as possible to prevent it from getting pluged up. If it does, it can cause pressure to build up in the t-case and blow the seals out of it which = leaks.

 

The actuator is pulling in as soon as I start motor with the transfer case in 2 wheel drive is that normal? Thanks