Hey, I recently bought a 1991 comanche, 4.0 ,5 spd, 4WD, and the 4WD always worked perfectly. I went to use it the other night and nothing. The light would come on but go off as soon as i started going. I tried low range and the truck was in low range, but no 4WD. To me this means the transfer case is fine, but for some reason the front wheels arn't engaging. Where do the vacume lines connect, i looked but couldn't really find them (I'm new to comanche's). Is there any other parts in the front end i should check? thanks