Hello everyone!

Can anyone please help me with this problem? My 4hi doesn't work. 4low works but switches a little slower than it used to. When I push the button to switch to 4hi, there is no reaction.[:@] When I'm driving 40mph and up the light between 2hi and 4hi blinks back and forth, but it doesn't engage the 4hi it stays in 2hi. My question is: is this a vacuum, electrical or mechanical problem? I was thinking (a good wile ago) about making my transfer case manual somehow. Like make a lever if possible or maybe something with the wires that go to the t-case. Is that possible? I don't want to sound stupid but the whole vacuum and "button" 4WD system seems to be such a junk, and I see a lot of posts here about it braking or people have different issues with their 4WD.

Any help is greatly appreciated!
Thanks in advance!!!

 

You have a code stored in your TCCM (transfer case control module)..it's probably a dtc #2 which is a tranfer case encoder motor failure...ground pin #13 of your DLC (diagnostic link connector) under the left side of the dash..right beside the park brake lever...then turn the key on engine off and count the flashes of the indicator lights on your 4X4 selector switch...if they flash twice then pause then twice again...etc..its a failing encoder motor..if it is 4 flashes then a pause..it's a failed TCCM....at any rate once you get the code..disconnect your negative battery cable and then your positive cable for 5 minutes.....then hook the battery back up and it will have cleared the code/s it should work again....if not repost...And if you have a problem again...you will already know what you need to fix it right...#2=encoder motor...#4=TCCM.....there are 2 other codes, but I've never seen either one actually set...Make sure you repost the results..PLEASE!

 

Yes!!This Posi-Lok 4wd engagement system is much better, and gives you more control over 4wd than the factory vacuum system. http://www.drivetrain.com/4x4PosiLock.html

 

What exactly does this "PosiLock" thing engage and how would it work on my Blazer? Will it engage 4hi and 4low or...?

I didn't do the code thing yet(didn't have time), but I will sometime this week.
I'll keep you posted

 

IDK..for sure..but I think posi-lock..just engauges your front diff....it has nothing to do with shifting the t-case which is what you have a problem with...lol.