Im new to this forum and was wondering if anyone could offer suggestions about my 4x4 problem. I have a 1999 Chevy Blazer, automatic. Four wheel drive is not engaging. All of my push buttons properly light up as they should - when they should. The problem is that it is not engaging. Replaced vacum actuator andhoses that were recently eaten due to a battery acid leak. Would love any help on this. Thank you.

Can I take my broken passenger and driver seat tilt handles and make something to make the four wheel drive work? LOL - just kidding.

 

Welcome to the forum, check the front axle engaugement cable right below the battery (it runs from the vacuum servo to the front axle) the battery's positive post leaks acid directly onto the cable and eats through the sheath eventually siezing up the cable.Post up if that's not the problem, we'll find it.

 

Thank you! Is that cable part of the cable harness system located under the battery?

 

The cable in question is connected to the vacuum acuator under the battery, it runs down to the front differential. If it becomes hard to move then the vacuum actuator can not move it to engage the 4HI Range. But your lites should indicate a failure...

Also if your TCCM has set a fault code in its memory you will only be able to get to 4LO and back. There is a procedure for this and if your OBD connector has the proper wiring then you can use it to find out what the TCCM has stored. (do a search for TCCM and fault codes) and you should find out how to do this...

 

Thank you Mark. I definitly have no lights indicating any failure. I will checkit out.

 

Replaced front axle engagement cable. Electric diagnostic systems are all ok. But four wheel drive is still not engaging. Any ideas? Thank you.

1999 Blazer Automatic
4x4 4.3L V6

 

Have you considered that your electric switch at the transfer caseis frozen? They do freeze up like a starter motor does. I can actually hear my motor click in and out of 4WD when the key is on and buttons pushed. Do you hear anything?

 

If you are sure that the transfer case is shifting to 4wd and you have replaced the vacuum actuator under the battery the next thing would be, are you actually getting vacuum to the actuator. It is possible that the vacuum switch (on the top right side of the transfer case) is not working. That switch is worth about $30.

 

Im still looking at everything...I really appreciate everyone's help with this - thank you.

 

I FOUND THIS LINK CHECK IT OUT
http://www.chevyavalanchefanclub.com...opic=41895.new