Im new to the forum so let me star off by saying HI, And i think this is a great forum.I have been on here for a couple of hours now and my eyes are starting to burn. Ive searched everything and cant seem to find out a answer so i figured id just ask. I have a 96 Blazer 4x4 LT. The problem is when i put it into 4low or 4high it "Clicks" up front even gives a little jerk but nothing. The lights on the buttons stay on like its working but the front tires dont spin. 4low pulls and gears down but no tire spin??? No codes, No nothing. I had it in the air when i first bought it just checking it out and i believe i remember seeing the front drive shaft spin, But not the wheels. Any answers to this? Its just like there is nothing in the frontend. Any advice would be appreciated. And just FYI im mechanically inclined just not to intelligent when it somes to 4x4s. Anyways Thinks in advance and Happy Thanksgiving.

 

Sounds like you have a bad 4wd actuator or transfer case vacuum switch. Either way it's a cheap easy fix. The actuator is under the battery, and to test it just take off the hoses and make sure it's holding pressure and that there aren't any tears in the diaphragm. If it is good, then your problem is with the transfer case vacuum switch. You can pick one up from the Help section at Auto Zone for about $15.00.

 

Sweet ill check that out a let u know how if it works. Thx for the advice

 

when you check the actuater, make sure the cable moves. I think it needs to move about two inches.

 

Check out the link in my signature - Common 4x4 Problems.

 

I got it fixed, After 2 years. Lol woww i figured it was something bad in the front end so never messed with it. It was a vaccum line goin to the vaccum ball. Fixed and works great. Thx everybody for ur help!

 

Conveniently last night when we were getting our first real snow of the year, I pressed the 4WD button and I just got a "blink blink blink". I discovered that it was an obviously corroded connector that goes to the TCCM located in the passenger side kick panel. I repaired it by using a connector pin from an old GM radio (same type of 100 series delphi connector) and extracted it using a small paper clip. Remember to SOLDER any connections that deal with moisture (even interior wiring) and also i put a dab of dielectric grease on the Delphi connector to hopefully prevent this in the future.

 

I have the same problem, the actuator holds vacumn but can't get 4wd engaged. where is the vacumn switch?

 

The actual device that is powered by vacuum is located under the battery. I suggest you consider checking out the TCCM located in the kick panel and verifying that there is no corrosion on the connector. Any spec of corrosion could mean problems. Please note that I've looked into this issue sifting through probably 100 threads and it usually comes down to one of the usual suspects:

1. Bad vacuum module (under battery)
2. Corrosion on the wiring connector to the TCCM (pax side kick panel)
3. Bad 2WD/4Hi/4Lo switch