You are welcome. So switch and wiring seem to be OK. Just curious... do you have the full 8 volts on the reference circuit?

 

FrankenCub: If you have the capability to solder, remove the 4x4 switches again, take the case apart to access the circuit board, reflow all the solder joints, especially at the connector pins.
Might help, might not, but only takes about 30 minutes of your time and a hot soldering iron....note iron not GUN. Do not use a soldering gun!

 

While I had it tore apart last night I thought about checking for the 8v ref but distracted myself and never did, I will check it today when I get back from town.
I'm not too sure I can solder anymore, well, anything that needs any accuracy. My hands shake too much from my back meds. I can take a look at it, if the joints aren't packed together like they are on the tccm I may be able to do the dash switch. What size soldering iron would you suggest ? I have a gun but my neighbor has a few smaller irons.

 

With more help from Lesmyer, I'm confident that the tccm is bad. After checking reference voltages it's half what it should be and there is at least one suspect looking resister on the tccm board that don't look right. Will be ordering a new one hopefully this week

 

Be sure to post back and let us know the final outcome.

 

Sorry for the long wait, our fridge crapped out and we lost about $300 of meats so I had to recoup the money for the Blazer. Anywho, I finally got the new TCCM, installed it today, it still doesn't seem to shift like it should. I did go back into 2wd much without as much hassle as was giving me before, but I suspect I still have another problem. Either on the front axle or transfer case.

 

Is the reference voltage at the TCCM now ok?

Les

 

Sorry Les, I haven't had a chance to check it again. I've been busy getting wood out for next winter, starting early this year, and getting my '71 GMC ready for a heart transplant which I started on today.
Had to run to town tonight and the damn Blazer put it's self in 4x4 Low when I was about to back out of my parking spot. As soon as I get my GMC done I guess I better be looking at the Blazer again. Now I also have a couple other problems showing their faces, hard start and squeaky control arm bushings (I think) but they will be an easy fix.

 

Let us know when you get back on it!

Les

 

Well back at the Blazer again, my wife bumped the 4x4L and now it's stuck there. As long as I'm checking the right reference wire, I'm not getting 8v. Only a bit under 3 or something.
edit: just went back out to check the LT GRN/BLK at the switch on the dash and I have 7.86v there...