Wont go into four wheel drive lights dont come on

SOURCE: 4x4 wont engage

There is a switch that has twwo wires going to it, it's located just above the motor on your transfer case,on the drivers side, one plug goes to the motor and the other goes to this switch, it's the motor that shifts it into low and high range, I'm not sure what the switch is called but it tells the front end when to lock and unlock.
Hope it helps

SOURCE: four wheel drive wont engage

If you have push button 4-Wheel Drive, it is recommended that you use it every once in a while, in order to keep gunk, rust, and corrosion to build up on moving parts. The mostly likeley (though not definite) reason would be that you let the 4-wheel drive unused for so long that corrosion has built up on the parts and the actuator that engages the 4-Wheel Drive doesn't have the power to engage it past the corrosion. You'll need to take it in to be cleaned, or to have parts replaced. In the future, every month or so, engage 4-Wheel Drive and drive around in some mud, grass, sand, or any other loose ground for a bit, just to keep the parts moving and clean.

The service Four wheel drive light is to alert the operator the system is not being read properly by the ECU.

If the ECU loses contact with or position of the Transfer case actuator motor the service light will come on. Same thing goes for the front diff actuator.

So it may be a bad switch, sensor, or an actual problem in the 4WD linkage. This is not a Oil Change light that you can ignore a few extra weeks - it indicates a problem that should be taken care of ASAP to avoid costlier problems down the road.
Thanks for using FixYa - a FixYa rating is appreciated!!

SOURCE: four wheel drive wont engage

I fought with this problem every year since I had the Sportage. And it was so frustrating to find out just when you really needed it, that you did not have 4-wheel drive. I replaced the hubs with manual hubs and I wish I would have done it at the beginning. They work great and are 100% reliable. Bottom line.. the vacuum hubs were a great idea that just plain did not work reliably. Save yourself alot of grief and money and just replace the hubs. Less than $200 including paying someone to put then on and I now can rely on my Sportage when I need it.

SOURCE: 1999 Chevy Suburban wont kick into four wheel drive

if it is electronic there is probably something wrong with the wiring..

but if it is manual...it might be the actuator........

SOURCE: 1994 chevy s10 blazer 4x4 push button type

small sylinoid on the top of the transfer case needs replaced. easy to do. it has three vacumelines going to it just trun out and replace like a bolt.