Chevrolet Repair: 4X4 problems, vacuum lines, chevy s10

Question
I have a 1986 chevy S10 that wont go into four wheel drive. It did when I first got it but now it wont go into four wheel drive at all. Could you tell me what the promblem might be and if it can be fixed? THANKS A LOT

Answer
allin, unfortunately there are several things that could be the problem. first ...does it shift into 4x4?if not check for seized linkage. if it does, does the front drive shaft spin? if not look for broken or missing vacuum lines to the engine from the transfer case. if the front shaft does spin start looking at the front diff actuator(diff lock). does the cable move? i think there is also a switch on the diff lock...check it for power and ground in and out of 4x4. hope this helps you out.