I have read the other posts and they seem to lead to the actuator and cable assy. Mine is fine but the vacuum stays on the actuator at all times. I'm guessing its the vacuum switch on the transmission. If so I may try to put a electric vacuum switch in line and control the actuator myself. Any other suggestions. Could it be the switch?

 

Check out the routing of the vacuum hoses. It is possible that someone has rearranged them, causing the problem you are experiencing.

But yes, more than likely, the switch is faulty.

 

Yesterday I un hooked the cable from the actuator and left it unhooked so i could drive it without 4wd until i get a switch. I tested it in my driveway and it was not locked but backing out of a parking spot at wal mart it was locked in again. is this possible with the actuator unhooked from the cable. The cable moves free.

 

If the front axle is still engaged after removing the vacuum line, then you have problems with where the cable connects inside the differential housing.