1999 Chev Suburban 1500 with front and rear ac - front blows cold, rear blows ambient temp. What is the route cooled air travels from compressor/condenser under hood to rear vents/blower? Is there a "blend air door" and/or a "blend air door actuator" controlling the flow of cooled air from the "front" to the rear vents and rear auxiliary blower? Professionals replaced compressor, compressor relay, expansion tube assembly, pressure cycling switch, receiver drier, evaporator core, charged refrigerant AND the expansion valve assembly for the rear auxiliary unit. Still blowing ambient air through rear vents using front or rear controls. The cooled air isn't getting there.

thats them one will be smaller then the other you want the large one it will be cool to the touch the small one will be hot and can give you a good burn if the syatem is working.....there is also two heater hoses going to the back so make sure you have the correct two like i said one is larger then the other the heater hoses will be the same size.........good luck thats them one will be smaller then the other you want the large one it will be cool to the touch the small one will be hot and can give you a good burn if the syatem is working.....there is also two heater hoses going to the back so make sure you have the correct two like i said one is larger then the other the heater hoses will be the same size.........good luck

there is a tee under the hood were the lines that are going to the rear unit branch off the front unit, start at thise tees and start working your way to the back and find were the blockage is allmost sounds like an expansion valve. let me try to explane what the expansion valve does, it is the heart of the chemical reaction inside the aircondition system, it is basicly an ourafas as freon is pushed threw the smaller hole it speeds up and causes a low pressure at that point in the system and it is at that point that the cooing starts in the system so the lines should be much cooler after the expansion valve, so find the rear expansion valve and see if the lines are cooler after the valve if not replace the valve. there is a tee under the hood were the lines that are going to the rear unit branch off the front unit, start at thise tees and start working your way to the back and find were the blockage is allmost sounds like an expansion valve. let me try to explane what the expansion valve does, it is the heart of the chemical reaction inside the aircondition system, it is basicly an ourafas as freon is pushed threw the smaller hole it speeds up and causes a low pressure at that point in the system and it is at that point that the cooing starts in the system so the lines should be much cooler after the expansion valve, so find the rear expansion valve and see if the lines are cooler after the valve if not replace the valve.