hi everyone new to the site. i got something going on with my 96 blazer 4x4 cant figure it out. i changed one vaccum line ,the one that comes off the plenum , i didnt have air coming out my vents. there is a line coming from behind the motor now when i hook it up the right front 4x4 acts like its trying to engage unhook it its fine. i am stumped all i did was change one line. can anyone help. thanks everyone.