I just did all my u-joints and before that I replaced my encoder motor on my transfercase on my 94 s-10 4x4 4.3l engine w. I am wondering if I could have put the encoder motor on wrong but I doubt it since the lights work and I can hear it turning when I turn 4hi on and off. When I have it in 4hi I cannot turn the front drive shaft so its probably the actuator since that is the only thing I havn't replaced. I did every vacuum line and every switch but I can't hear the front engadge. I read my tccu code and I'm getting the #1 code - RAM Standby Power Fault which I guess is common when you disconnect or reset the tccu. I'm gonna check my vaccum lines tomorrow.

Is it safe to rule out the transfer case since it locks into place when in 4hi?

And for anyone looking, here is a helpful link to 4x4 problems. https://blazerforum.com/forum/tech-a...ill-help-7180/

 

My 97 did the same thing when I had to replace the actuator. It would lock in to 4 hi and low, but the front wheels had no movement, so I pulled my battery and tray and found the actuator had a tear in it, not allowing it it hold vacuum. So actuator is my best guess.