Front axle in 4X4 all the time...
 

Long story short.

My girlfriend drove my '99 Blazer last winter and failed to notice (and tell me) that, at some point, the 4X4 engaging mechanism for the front axle failed to release and kept the axle live most of the winter, even when driving on dry pavement. This chewed up my snow tires and, at some point turned on the Service 4X4 indicator light on the dash. Is there an easy way to return the vehicle to 4X2 mode until I can get the thing truly fixed? What commonly causes this? Does this sound like an actuator failure or could it be something in the front differential. What should I be looking for?

packrat

3 or 4 button system ?..If the front axle is staying locked , either you have constant vacuum or the cable may have seized....if its a 3 button system the T-case vacuum switch may be stuck.

I want to say 3-button. I do not have the vehicle nearby to check. From memory, I know it has options for 2X4 High, 4X4 High, 4X4 Auto, and 4X4 Low. If the cable seized, then I will probably have to pull the battery to see if the actuator moves. I was under the impression that if the cable failed, the front axle would fail in 2X4 mode. It may be a bit before I can get to it. It's 20F outside right now and my garage is already occupied. Thanks for the reply,

That's the four button, the three button does not have an auto 4x4 button

Sounds like hoses have been mistakenly switched on the solenoid and vacuum is being trapped in the actuator when the solenoid closes (only one side of the solenoid is vented). Same exact thing happened to me.

Select 2WD. Jack up right front wheel (only). Engine running. Can you spin RF wheel? If not, disconnect hose to the actuator at the solenoid. Now can you spin the RF wheel?

Good luck and best wishes for a successful repair.

As per what Les says . I believe the top hose spigot should run to the front actuator.....I have seen a picture that shows the bottom spigot going to the front actuator and for my tests that picture showed wrong. definitely test it and please let us know.

Thank you all for the help. I will check on what you suggest, but it may be a week or more. I have to retrieve the vehicle (it's 8 miles away), and what with it being dark by the time I get home, I will probably have to wait until a weekend. Guess what. Next weekend is Christmas. Probably not happenin then....