Rear A/c Not Blowing Cold

[cajunsuperduty]

2002 Yukon Here. Front A/C is blowing ice cold and working fine, but rear A/C is not blowing cold. Not even a little cool. I have tried both front and rear controls for rear A/C, but cannot get it to cool at all. Any suggestions would be greatly appreciated.

[cajunsuperduty]

A few more things to add here. I wondering if there is some sort of electronic control that diverts air either thru the heater core or the evaporator in the back. The large a/c line going in the the evaporator in the back under the vehicle is cold and the drain line is steadilly dripping when the a/c is on. To me this means that it is cooling. The air coming out of the vents is pretty neutral maybel slightly warm. If I turn the thermostat all the way to hot or all the way cold the temp of the air does not change. I am thinking that there is some sort of diverter not working that is causing the air to blow thru both the heater core and evaporator. Is this possible?

[ryan632]

You thermal expansion valve filter is completely clogged. You will have to take your rear passenger side panel off and open the air box, and remove the evap core. But first you will have to have your freon recovered.