I have a 2000 jimmy up until today the 4x4 worked great . I push the button and nothing. i know the could be a bunch of different reasons why its not working. i just kinda want some ideas so i can head into the right direction to fix this. thank you

 

Do you have a manual transfer case of Automatic. If it is a automatic transfer it could be the vacuum actuator under the battery having a hole in it and causing the vacuum actuator not to operate. It could be a number of different problems but this is where I would start.

 

3 button switch on the dash, or a 4 button switch?

 

Just had mine quit when I needed it. I just opened the hood and listened around and hear a vacuum leak. There's a little "T" splitter on top of the engine with a very short 90 degree on it. The 90 was leaking. It helps to move them around a little and you might hear it. I've had the older style and now have the newer style blazer and both times it quit it was a vacuum leak. I just robbed a piece off of a longer hose and fixed it. On the 2001 the push button 4x4 the light was flashing.

 

Suggest checking fuse first. But need more details as to what the 4x4 button lites are doing, how many buttons, does HVAC work 100%.

 

First thing to do is listen for the transfer case. Open the door push the buttons, you should hear it engage. If it does get underneath and try turning the front wheel driveashaft. If it doesnt turn you know its not the t case and most likely a vacuum problem. Sometimes my light dont light up also, but it still works. Good luck