Main ac not cold but rear is

[stanley hall]

I have a 2002 Eddie Bauer expedition. The main ac blows warm air. The rear blows cold. At idle low side 37 high side 190 ambient temp 90 degrees. Small line on evaporator coming out of firewall sweating and cold large line warm. Could problem be a blend door?

 

[Joseph Burgess]

Waiti g to hear a reply to this as mine does this from time to time but have found that if i turn both on ay same time my rear will blow cold faster than the front , and the front kinda plays catchup ive got about 42 psi on the low side currently