4x4 not working

I have a 93 s15 that the 4x4 is not engaging.

Can someone help?

Electric or manual?

You may have a vacuum line issue. There is a vacuum line that controls an actuator in the transfer case and the front diff. If either one of these lines has come loose it will not engage properly. Check these lines. There is usually a valve body in front of the wheel well on the passanger side under the hood.

Engage your 4WD, with the engine off, reach under and see if you can turn the front driveshaft. If you can turn it, the transfer case is not engaging, if you cannot turn it, the transfer case is engaged. STEP 2 - If you cannot turn the driveshaft, jack up one front wheel, engine off. If the front wheel turns, the front axle is not engaged. If it does not turn, you are engaged and it might only be an idicator problem.

More than likely, the front axle is not engaging and that could be the vacuum actuator switch on the transfer case is bad, The actuator under the battery is bad, the cable from the actuator to the front differential.

I had the same problem with my 93 S-10 Blazer. The actuator is most likely bad. It's located under the battery tray on a 93. Remove the battery and then the battery tray. There's 5 or 6 bolts and 2 go through the inner fender. There will be a vacuum line going into a housing and a cable comming out of a rubber bellows going to the front differential. On mine the rubber bellows was torn to pieces. Auto parts store said it was a dealer only item. Local Chevy dealer wanted around $90. A friend found me one in a junk yard for $5 and it works great. If getting a junk one make sure to test it. Push in the bellows and plug the vacuum port with your finger. It should stay collapsed. Let your finger off and it should pop back out. The actuator on earlier s-10's (80's) is located on top of the fender where the battery acid and fumes won't get to it. Look for one of those if you can find one.

thanks i'll check it out