We recently got this blazer that had been sitting for quite a while. It runs great but won't go into 4wd. It apparently had this problem before and there was a bad vaccuum line. We have found a diconnected line and a couple that are damaged or missing (probably mice) We can't find where they feed from. Repair manual was useless for this problem. Does anyone know where the vaccuum lines lead from to the transfer case etc... Thanks for any help with this!