4 WD is electrically done in the front axel pumpkin, the solenoid may be gone you can check it by removing the solenoid and have someone else put it in 4 WD with the ignition on and watch the solenoid. They do all the time and are expensive parts at the dealers, parts stores are cheaper and some places even sell a mechanical cable to fix it so the electronic part is never a problem again.
Technology is great when it works,
and one big pain in the ass when it doesn't
Detroit iron rules all the rest are just toys.
[This message has been edited by 84fiero123 (edited 11-17-2014).]