ok i have a 95 s10 blazer 4.3 4x4. been having problems with the 4x4 on and off mostly on. this is the problem you press either 4 hi or lo nothing happens but the transfer case module clicks like 4 times and stops no lights come on.other than the 2wd light. also if i take off the transfer case motor and put it in 4x4 manually 4x4 lo and hi works but have to lay under truck to put it in. here is all the parts that are new on the truck or what i have tested.
NEW:
relay
vaccum lines
vacuum switch on transfer case
new speed sensor
new transfer case motor
sensor on front diff
4x4 switches

CHECKED:
my buddy has same truck and i tested his multiply parts in mine
4x4 kick panel cpu
transfer case module
tested 4x4 vacuum under battery holds vacuum...
checked for loose wires or corrosion none....

with all that said ...please tell me whats wrong with this thing driving me crazy thanks...

 

if you have any input please anything will help..cause i have no idea anymore thanks...

 

have you considered the wires going into the switch module? look at this link;

http://kylestubbins.com/node/11#comment-2845

I recently had this problem with my 2001 blazer

 

I have just fixed this exact issue and I found Most of the info regarding the 4WD not working on this site is complete BS at least when speaking of my 1995 blazer...

I know I just fixed my problem with the 4WD on my 95 Blazer and Although the places to look were all listed on this forum but just not where they actually are based on my model and NO WHERE near correct sequence to correct the issue...

I spent 3-4 hours looking and reading on this site and there was NO helpful info...

So For a 95 the TCCM is NOT in the PS Kick panel it is in the center of the dash just below the heater controls... So the Box you changed in the kick panel with your friends truck was not the TCCM it is most likely the restraint Module…

Now For those who always say the front axle is the problem when any question was asked why my 4WD is not working should think about what they are saying based on what the question was asked...

I say this because numerous thread say "My 4wd is not working and when I push the 4hi button the lights just flash" well that has NOTHING to do with the front axle, the 4WD is flashing because the Motor is not shifting into the gear you have selected and that is either:
- The Shift motor is not working
- The 4WD switch on the dash is not working
- The TCCM is not sending the signal
The Front axle ONLY comes into play once the T-case locks into gear and the light is on in the corresponding gear and the front wheels are NOT TURNING..

Now In my Case the TCCM was not sending a signal and I listened to the incorrect info regarding this problem and Bought a New Shift motor only to find the same problem I was lucky and my parts guy took back the motor, I then bought a new switch because it was cheap and mine was a little worn out but that was not the issue and then To find where the TCCM was located was a pain as Even the dealer did not know it's exact location but after a little looking around I found it and it is just under the heater controls on the 1995 Chevy Blazer...

I Hope this info helps you fix your 4WD as Mine is now fixed without having to replace the TCCM I was able to just unplug it and use some dielectric grease and reinstall it without too much cost to me…

 

Jeepmansoffroad--- so what exactly was the problem?? why was the tccm not sending signal???i have a new t case motor, new 4x4 switches, t case module from a friends blazer the one in dash and his 4x4 works fine, no corrosion on wires, all new vacuum lines, new vacuum switch,new front diff sensor, diaphragm was checked, new speed sensor. i checked all grounds there good, fuses are good....

 

What I did to figure it out...
After I installed a NEW T-case Shift motor and found the same problem I removed the Motor and replaced it with my old one and let it dangle and Had a friend push the 4x buttons and I watched the T-case motor and Saw that it did move but only into 4lo or 2hi and nothing else...

I then pulled the TCCM out of the dash and While holding it I pushed the 4x buttons and felt the TCCM clicking but nothing was working... In my Case it was just a glitch/loose connection I think because once I unplugged the connector and Added die-electric grease and plugged it back in It worked fine...

Did your TCCM click when you had it in your hands and pushed the 4x buttons? if Not I would be checking the fuse which I think is #19 in the fuse panel on the side of the DS Dash....

Good Luck...

 

ok. wish it was as easy to unplug and plug it back in..i tried no luck..dam...and yea the fuse is new. and yes its clicking like 4 times and stops. checked wires and checked for corrosion but noithing.....

 

ok change my transfer case module now truck shifts good trans case motor turns in 4 hi lo and 2. but front end work kick in the vacumm actuator has vacuum when u put it in 4 hi it sucks in but wont engage...now whats wrong anyone?

 

The actuator needs to pull the cable 1/2" to 3/4" to fully engage the collar inside the front axle. If the cable is being pulled that amount, then there is a problem with either the shift fork or collar inside the front axle or possibly the cable has become disconnected where it connects to the shift collar.

Here's what it looks like inside:

 

This sounds like something I ran into fixing my98 blazer 4x4 system. I bought and installed a new tcase vacuum switch which i bought from Autozone, and as it turns out, it was not fitting tight enough to seal everything up and was not keeping enough vacuum to pull the actuater all the way. I could see it move, feel it move, but just needed a lil more umph to get it pulled all the way and lock inthe front axle.