oil in hemi
From : mac davis
Q: the diverter door that controls where the air blows - defroster vents dash vents floor vents is vacuum-operated. the blend air door controls how much air passes through the evaporator vs. how much flows through the heater core is mechanically operated - theres a cable that runs from the control dial to the door. quick test for that - turn blower on high select dash vents. turn the temp. control from full cold to full hot. if you feel a difference in temperature coming out of the vents the doors probably working properly. dodge did not shut off the water on your truck if lines going in are cold ck to see if blend air door is working and that would be a vacumn operated flapper door i guess. i was thinking about that also. ron .