Ac Cooling

JoeBoxer1130 said:

2003 Tahoe LT
Does anyone know why my ceiling AC vents blow out colder air than the front vents???
Im not low on coolant last time I checked.
Any tips will be greatly appreciated.

Click to expand...

TJ Baker said:

Simplest answer is the two vents come from different evaporators.

The air from the ceiling outlets comes from the auxiliary system and the air from the panel vents comes from the front system.

Further, the front system employs a fixed orifice as a refrigerant meterimg device and the auxillary system uses a thermal expansion valve.

A TXV (thermal expansion valve) system can maintain better control of the evaporator core temperature than a fixed orifice system can.

That's my guess....

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mikez71 said:

Could said fixed orifice be clogged, causing sub optimal cooling?
Hopefully relatively easy/cheap to replace? (though still requiring a charge)

If the front blend door actuator was failing/partially stuck? .. are you able to blow heat in the front?

And are you on recirculate?
I once noticed fresh air was really warm with my A/C off, though I was missing my cowl seal at the time..

Click to expand...

mikez71 said:

Could said fixed orifice be clogged, causing sub optimal cooling?
Hopefully relatively easy/cheap to replace? (though still requiring a charge)

If the front blend door actuator was failing/partially stuck? .. are you able to blow heat in the front?

And are you on recirculate?
I once noticed fresh air was really warm with my A/C off, though I was missing my cowl seal at the time..

Click to expand...