Why does 2004 Jeep Grand Cherokee blower run but air vent pressure is low?

Answer 1

I had similar symptom. Seems the door in the vent housing that selects recirculate or fresh air ( which is controlled by a vacuum valve ) broke. The pivot that controls the door movement snapped so the door falls down and blocks the incoming air flow thru the heater or air conditioner. End result very little air out of the vents. Pretty tough to repair the vent housing is against the firewall behind all the dashboard and the glov compartment. So you basicly have to remove the whole dash to get to the heater vent box.

That's if it is the same issue I had. Jeep told me was $1000 to repair.