do you engage 4WD manually or via the button on the dash? if its the latter then your actuator switch is probably bad. tweek
If it is 89 to 95 it has a central axle disconnect, they go out all the time. Check that.
the transfer case motor has to be replaced
check vaccume motor (usually mounted under battery box they rust out you can also find it by following cable from front differential.also if that is not problem on the transfer case there is a vaccume switch that has 4 lines going to it the switch sometimes gets stuck
No. The buttons operate the shift motor on the transfer case. The only way would be to swap in a manual transfer case.
It may have the original transfer case that was recalled
Sensors got wet
faulty actuator switch. GM had some problems with these.
Starter selenoid no good
A collision or hitting a bad pothole
Yes it will. It has to work.
bad transfer case
bad clutch cable, or not enough oil on the clutch plates.