I've got a 2011 F150 that has been giving me some fits over the last few weeks. It all started when I was on the highway and heard a big hissing sound for a few seconds. After that I lost all cold air.

I took it to a shop and they said it needed a new compressor. Put a new compressor in and recharged the freon. This worked for a few days until it stopped blowing cold air. It had lost maybe 10-15% of the freon so they then replaced the schrader valves and recharged the freon.

About a week later I lose all cold air again. The shop said previously that they had checked for leaks but found none. I took it to a different shop today and they call and said the A/C had worked fine since I brought it in. No issues at all and the freon level was good.

Do you guys think this might be a blend door issue? Any other guesses? I was thinking evaporator until it started working find again today.

Thanks ahead of time.

 

Do the radiator fans come on when you turn the a/c on?
.

 

I just tried it a minute ago from a cold start and the radiator fans did not come on.

My vehicle has all manual ac controls if that matters.

 

The fans should come on almost as soon as the a/c compressor kicks in (depending on ambient temp), otherwise it will trigger the pop off valve (pressure release, think loud hiss, loss of refrigerant) or the pressure switch will just disengage the compressor.
.

 

Can you elaborate on the pop off valve? Would that affect one side or the whole system?