a/c cold in back but not in front

[BenJammin74]

2002 Expedition 4.6
I have ice cold air in the rear but the front won't get cold. I took it to a shop recently for them to check/add refrigerant and it was ok. They said the heater valve was bad, causing the heat to be on all the time, preventing the air from being cold. It made sense at the time. I did a few tests on my own that disprove that theory. I let the exp. sit all night, then started it in the morning and turned on the a/c. It was cold in the back but only sort of cool in the front. I let the engine warm up and then turned off the a/c. The air got slightly warmer but no hotter than ambient temperature. It seems like the refrigerant is not being circulated through the evaporator. I talked to a mechanic buddy and he said it could be the "expansion valve" but he's a Chevy guy and didn't know much about Expeditions. So I'm hoping someone else on here has had this problem and knows what this is. I'm tired of sweating!

 

[BenJammin74]

still need help

 

[BenJammin74]

Can anyone help?

 

[JUST4FUN]

pull off the hot/cold knob and make sure its not cracedand turning the shaft,

 

[BenJammin74]

nah its definitely not the knob. it won't come off anyway. I can turn it either direction and it stops solid on the marks, it doesnt free spin as if it were broken. Its working anyway, because when I turn it to hot it gets hot and when I turn it to cold it gets as cool as it would if the a/c were off (ambient temperature) its got to be something preventing refrigerant from reaching the evaporator.

 

[lakmflx]

I feel your pain on not having a/c..

I live in Florida and not having a/c here is KILLER.

In my case though i have a leak somewhere in the lines, took it to a shop and they shot some dye in there to trace it... have to take it back next week when i have the time for them to track it down.

 

[Maddog11]

I would lean towards either the blend door/actator or a vaccum leak. There is a slim chance of a defective control head but not likely!