I have a 1994 blazer Tahoe edition with the 3 way switch and I can’t figure out my problem I’ve gone through all the vacuum lines and wiring can’t figure out my problem. Also is there anyway to take the motor off the transfer case and build a lever that attaches to it to make it manual?

 

First, a couple of questions about the problem.

What happens when switching to 4HI?
Does it switch to 4LO? (Truck needs to be stopped and in "N" to shift.)
Does it switch back to 2HI without blinking?
What is the switch doing?
Do the lights blink and when?
Does it sound as it is shifting?

You can take the electrical motor off but at the same time it is the encoder for the transfer case control. So you would need to make a cover plate with a simmerring for the shaft, fit supports for the shift rods and cut through the tunnel for the shift lever. Then you need to tackle the front differential locking by either electrical or mechanical actuation, depending on the transfer case position.
The encoder motor position will also actuate the front differential solenoid which applies vacuum to pull the locking cable.

The encoder motor is known to go bad. Replacements are available at around 200$

 

ok so I’m not sure where the OP went here but really same issue for me but in a 1998 Jimmy SLT 4dr. I’m a little laid up sick right now during the time I had allotted to deal with my problem. So research never hurts.

It was having blinking light issues on the buttons and a tuff time coming out of low range. Now I have no blinking light issue and no issue with switching from high to low range but absolutely no front engagement.
I did switch to a standard transmission and very recently put a jumper across the clutch safety so I am thinking it would now be showing the computer that it is in neutral? My plan was to do a vacuum test Thru the system and see if that leads me anywhere

Shawn