Strange AC problem with 2003 V6

Some times it works, and some times it stops.
Last Friday I drove on the freeway for an hour and it did not skip a beat.
Last Thur, I drove it home from work from work. It would work for a while, and then start blowing hot air. Here is a strange thing, the AC is on recirculate, when it starts blowing hot air, if you turn the AC off, the air temp will drop. It almost seems as if the AC in on or that the heat was on. After a while the AC will start working again. It might work for a few min or for half an hour. It might not start working again untill after I get home (about 30 min). This issue is getting worse, at first it would only stop working for a min or two. What do you think? At idle when you turn on the AC you can feel the compressor kick in, but you may or may not get cold air.

 

Sounds like you have a low charge on the Freon,,, so your evaporator core is freezing up, hence the intermittent cooling,,, is the air blowing out the vents the same velocity all the time or do you notice the air not moving out the vent like it should some of the time and then back up to where it should be, which would indicate the blocked evap from the ice, air won't pass through it.

 

It cant be ice, last friday it ran all the way home From LBC with no issues. that was 45 min to an hour.
On Thur, the compressor was running, engaged, and it was blowing hot air, like the heater was engaged.
The air velocity is unchanged, working or not. I seems as if the heater is turning on and off.

 

if the a/c is on and the compressor is running but its not blowing cold in the truck then open the hood and feel the big line, if its ice cold then your problem isn't with the a/c at all but its the heater is running and keeping it from cooling. the heaters on these trucks works good and if the heater is running the a/c cant put out enough cold air to do anything more then just make it feel warm.

if the heater is running then you might need a new heater control valve located on the center firewall just before the heater core. sometimes they can get corroded and start leaking at times but since you have an 03 it should be all plastic so most likely its going to be the heater control module and they are pricey (around $150) unless you get a used one from salvage yard