(1993 S10 Blazer Tahoe 4.3 automatic) I got this morning to play in the snow and found that my 4x4 no longer works . So I ended up stuck and had to get pulled out my buddies Ranger .....

I put the blazer into neutral and put it into 4 high the gears grind a bit and it feels like it goes in but the confirmation light doesn't light up, so I put into 4 low it made worse grinding sound then feels like it goes in but again no light. So pull it out of 4 low it grinds into neutral-4 high-2wheel.

wondering where I should start looking with the kiss (keep it simple stupid) approach.

 

I believe there is a vacuum actuator under the battery tray, from that there is a cable to the front differential. I have similar problems, I just haven't started to fix it yet.

 

sweet thanks I'll look into it.

 

What a lot of guys do when you don't wish to fix the vacuum actuator is just take that cable and extend it into your cable with a cable form the bicycle store so that you can just pull it manually. However, upin closer inspection you may find that the vacuum lines are just cracked or broken between the actuator and manifold. Can replace those lines, or make a manual cable yourself.

 

I will most likely be making it manual, so I don't have to deal with all the vacuum lines. Thanks for the reply's guys they help a lot.

 

Before replacing anything, try this.. Pull the TCCM fuse under the dash (drivers side fuse panel) for 30 minutes at least, longer if you forget about it.

After at least 30 minutes, put the fuse back in, and cycle the key on and off 5 times

just to the on position, not starting the truck.
Turn the key on, watch the 4wd lights, once they blink once like they usually do, turn the key off, repeat 5 times.
This will reset the rom/ram on the tccm. If that does not fix the problem, there is more of a problem.

Report back with what you find.

 

awesome it works great after doing the fuse... thanks! another question how do I check the transfer case fluid/what fluid do i use? It grinds every time i out it in and take it out of 4hi/4lo.

 

i used my 4wheel drive yesterday morning then has to use it again in the evening, it worked fine in the morning but in the evening the lights on the button flashed then went off and nothing. when i start it the button flashes but nothing when pressed. thing the fuse technique would fix this or is it something else?

 

I would try the fuse, do as I described in my last post, and see what results that you have, and report back.

 

I am glad that worked for you, it seems as if the TCCM has windows for an operating system LOL
It gets confused easily, so will need a reboot ever so often.