How to test if 4x4 works

Hello fellow blazer owner!
I had just bought a 91 blazer (s10) and was told by the previous owner that he thinks the 4x4 does not work.
What are the ways to check?
Thanks.

Kick it into 4x and make a tight turn. You'll feel it grabbing if it works.

do a burn out on a low traction surface.

Hello fellow blazer owner!
I had just bought a 91 blazer (s10) and was told by the previous owner that he thinks the 4x4 does not work.
What are the ways to check?
Thanks.
find a mud pit see if it works if it doesn't make sure you have a phone number of a tow company handy...just kidding go to a gravel lot or soming and slam on the gas and if it works you will take off fast if it doesnt it will be slow taking off

What does the inside indicate? pull lever or push button?

If its pull lever all the lights on the indicator will come on, the one that looks like an drivetrain and frame to our vehicles.

Its a 5 dollar fix, and about an hour of time and patience to replace if its the tcase switch thats toast. I just replaced mine, but mine didnt work for sure.

Its a pull lever and i dont see any light that comes up on that pic of a drivetrain on the side .
whats the chance of that light bulb in there getting burned up?
And is there a way to test the Axle Actuator?

Is the Tcase switch located behind the battery? I see one switch in there witha green conector and it has a vac hose connected on it.
If so, can i jump the 2 wire to see if the 4x4 will kick in?
Where did you buy the switch for $5?

I would avoid the truck, sometimes it will cost more to fix the 4x4 than it costs to buy the truck.

I have checked the Vac actuator and it does seem to hold the vacuum although when i start the engine and shift it to 4x4 and then i checked the vac hose going to the actuator, i felt no vacuum.
There is also a switched which is tapped to that same hose and i wonder what that was. some kind of a vac switch or sensor?
Now I will have to check or replace that Tcase Vacuum switch, has any1 bought it form a local autoparts store or its only a dealer item?

Here's a picture of what your looking at
http://www.kvsbt.com/stu's/t-case%20vaccum%20switch.JPG

I took my T-case out last week, and from the looks of it the switch is a little hard to get to, but not imposible.

I don't know if it's a parts store item or a dealer item.

Although I can't promise that this switch works (I only used a 4x4 posi lok system in my Blazer) if you want just send me an envelope with enough postage (I live in Canada and it would need to be Canadian postage) and it's yours.

it looks hard to get to. Ill check if all the vac hose are conected on it though. if i cant get that switch out ill probably go with your posi lock system.
thanks!

Posi loks are JUNK!

I'm sorry but it's true.

They're made out of hardware store hardware but they charge a mint to buy them. They don't respond to their e-mail when you ask for any updates to eliminate their problems.
I e-mailed them over 4 months ago without a single response just asking them if they have better hardware available.

However if you really want one let me know and I'll sell you mine for 1/2 the price. You can eliminate the only real problem with some epoxy (It's a sliping cable housing, and I'd show you where it's slipping)

I'll be kinda busy for the next while but if you'd like some pictures of it to try making your own I'll take them and post them here.

I'm switching my entire drive trail including the differentials to full sized parts so I don't need any of this stuff any more.

Thanks! but i found the problem, it was a vac fitting that connects the hose that goes to the switch. it was melted coz it had touched the exhaust pipe.
No wonder there were no vac at all at the 3 hoses that was conected to Vac Switch.
Well im going to my work today and im getting me those vac hose.
Thanks for the help!

That's my favorite kind of "fix" or repair. Glad you got it.