2004 expy with 4,6L ac problem

[keithnra]

my wifes truck does some wierd stuff with the ac,
first off, if its really hot outside and the ac is on high and u take off quick, it goes to defrost and heat. the only waY TO change it is turn ac off and let it sit for a min then when u turn it back on its back to cold or cooler the ac lines under hood feel really hot to touch. the back ac works fine but the front ac only seems to cool like it should at highway speed
If its the front expansion valve how much Freon will I need to fix it

 

[keithnra]

i figured out that it doesn't go to defrost just goes to blowing heat out of the v ents. What does the actuator behind the radio control. is this the actuiator that controls the heat and cooling door.

 

[keithnra]

Still donthave this figured out

 

[stamp11127]

The blend doors are usually driven with electric motors while the selector switch controls the different modes & runs off engine vacuum.

Are you sure that heat - as in very hot air, is coming from the vents when the a/c stops blowing cold?

Usually when the a/c has a problem with the refrigerant side both the front and rear a/c will quit.