Have a 03 Escape XLT. My issue is a/c works fine until I get into heavy stop & go traffic or lengthy idling. It'll start blowing hot air. This continues until I get into highway conditions with more continuous driving.
This has just started. Didn't have problems last year. I'm in Alabama & desperately need the a/c!

 

As long as the air flow doesn't switch to the defrost vents, you probably do not have a blend door issue.. My bet is your system is under performing with a low refridgerant charge. You really need to connect a set of pressure gauges to your system to verify and prevent over charging it.

 

thanks!