A/C Vents and vacuum lines

[z1179]

So i got my A/C blowing cold on my 1989 jeep comanche but the air is blowing out of the upper vents instead of out the front, any idea what could cause this?

[HOrnbrod]

Probable broken/cracked vacuum line. Check in front of the battery where the plastic vacuum line goes through the right front bulkhead to the vacuum canister behind the bumper. They usually crack in that general area.

[Marine1Texas]

There is also a vacuum line under the dash near the driver side.

[ParadiseMJ]

Really, any of the HVAC side vac lines can break, chafe or crack.  The one going TO the ball and the one(s) coming away from the ball to the pink or black HVAC at the firewall, or the ball itself.  Easiest way to find a leak is a smoke test.  I don't mean an expensive machine...I mean a cheap cigar.  Light, puff. blow into line.  Look for smoke.  If you can't do that, just a careful inspection should turn it up.

 

The driver side lines don't really affect the HVAC side except the SOURCE line from the intake manifold. 

[cruiser54]

[Marine1Texas]

If all is good from the ball and in to the cab,

There is a actuator that moves the vent door under the dash as well. Start from the ball and move in to the cab.