Warm air from one a/c center vent?

[X5chemist]

Keep the three blue dots in the middle. Mine has the same problem. If it goes to two dots, A/C temps don't go to <40 degrees. I'm going to wedge something in it or use black tape. I have a new heater control valve to install. I thought it was the problem until I turned the knob to three blue dots. Since I have it, I might as well install it. 150k+ miles is a lot of use. Winter is coming too.

[andrewwynn]

If it rebounds off 3 dots something's wrong with the cable or the flap it controls (like a leaf caught). It's supposedly a big pain in the ass to work on the blower system but I've heard you can pull the radio controller and HVAC controller to work through the dash center.

[X5chemist]

Can the blower motor be replaced through the radio/HVAC gap? Mine is showing signs of bearing noise squealing. The rear one squeals for sure. I need to look at replacing the center blower.

[EODguy]

Originally Posted by andrewwynn

If it rebounds off 3 dots something's wrong with the cable or the flap it controls (like a leaf caught). It's supposedly a big pain in the ass to work on the blower system but I've heard you can pull the radio controller and HVAC controller to work through the dash center.

The rebound is most likely the guide reel/pulley worn center hub that allows the reel/pulley to wobble letting the cable ride up the edge. God help anyone that has the cable pop off who doesn't have baby arms...

Sent from my SM-A730F using Tapatalk

[TECN1K]

Any update on this? Mine is completely seized. I'm under the glovebox, bowden cable disconnected
and cannot move the actuator more than a few MMs in either direction. Possible the door itself has dislodged? Really don't want to pull the dash and to tear apart the HVAC matrix box.....

[Homerlovesbeer]

Any updates?

My RH vents are noticeably warmer than the left but the car still gets nice and cool.

[BondoBen]

'03 3.0l same problem-ish. Mine starts up at first cold......then gets warm......then goes back to cold......then warm as you drive. Have yet to put a driving condition to the changes. Seems at random. Anyone know what exactly controls (flap/door) the left vs right side temperature blend. Live in Houston. Heat I have plenty of. Thanks.

[andrewwynn]

Warm and cold cycle often from evaporator icing up. He get freon tested. When freon runs low it causes a drop in the EVAP temp because the relative difference in the high and low pressure is greater so there's more heat transferred than designed.

[BondoBen]

And this would occur in one of the four vents? I've read where people have checked the Freon level but never understood how/why one of the four vents would be affected. I'll check that but in the mean time......how does it just affect the one vent with only one common evaporator? Thanks.

[80stech]

No, that is more BS spewing from the andrewwynn volcano, what happens when the freon is low is that the very first part of evaporator gets too cold while the outlet with the expansion valve doesn't get cold enough so it starts the icing cycle which then progresses because there is less and less airflow for heat load and at the same time (with IHKA anyway) the evaporator temp sensor is in only in the airflow after the evaporator and not contacting it so is sensing warmer as the evaporator freezes. The pressure differential is NOT greater and there is NOT more heat transferred TOTAL BS.

@OP try using recirc, if the evaporator is freezing that will help a lot.