I've been having issues with my Air Conditioning over the past year.
My usual shop recharged it (with a dye indicator) and told me to drive around for a while until it didn't feel cold anymore. At that point, they found a leak at the condensor (sits in front of the radiator) and replaced it. Since this was the end of the summer, I only used it on one or two occasions before it became un-necessary. Fast-forward to this Spring and on one particularly warm day, I noticed once again that the output was only "cool" and not very cold. Over the summer, it was much of the same, and since our summer wasn't very warm (until recently) I didnt use it very often. While out of town, I had a minor mechanical issue that required the attention of another shop. They noticed that the condensor was leaking...but I declined any repairs since I wanted to take it back to my usual garage to have them pony up for a replacement, since this one had less than 6 months on it.
Once at my regular shop, the new guy told me that it "probably got hit by a rock" and that they wouldn't replace it under warranty...so I took my business elsewhere. The new shop replaced the condensor and recharged the system, but on our latest trip (last week) I noticed that the output still isn't cold at all....just barely cool.
If I turn the temperature control ****, I can feel the air temp go from hot to cool...but never cold. My old '97 OBS had an AC that would chill a 6-pack, but this one....not so much.
So before I take it in yet again, I'm just looking for some advice....
Is there something that I should be checking to confirm operation?
If I turn it to MAX AC, the output is "slightly" cooler but again, nothing compared to any other vehicle I've been in...even wifey's RAV 4 blows colder air than this one.
Is there a baffle somewhere that might be hanging up?...a filter that might be dirty?
I'm at the end of my rope on this one...I've spent over $2000 in the past year trying to get some cold out of it.

 

System is undercharged, system is overcharged, blockage in the system, compressor is failing……can be any one of these. Get the manifold gauges out and start with the high and low-side pressures.

— Dave

 

Need to find out where the leak(s) actually (is/are) and go from there.
11-16 trucks are notorious for leaking evaporator cores and evap temp sensors that stop working. Both require the dash and the HVAC box to be pulled.

I have a 2013 and the AC will get the interior COLD sitting at idle on a 95* day in the sun after I fixed the leaking schrader valves and recharged with the specified 29oz.

 

Is there a way to test this evap temp-sensor....I mean without the Forscan thing?

 

Forscan is the easiest and cheapest way I'm aware of to monitor that PID if you don't have anything else.

 

Might be worth your wile to stick a thermometer into the center dash vent and see exactly how cold the AC is getting. At optimal scenario it should be about 45°F, but once the actual temperature and humidity are taken into account, you could get a different outcome.
So when you say it blows cool, are you saying it's 50, 60, 70 Degrees?

 

My son has a 1990 F-150 he recently bought. The seller said the AC needed a recharge. We took it home and charged it with R-13A with dye in it. It only blew cold air for 3 days. Under the black light we say leaks in the compressor, the hoses (multiple locations). We decided to do the work ourselves and bought some expensive special tools/vac pump, a new hose set, a new compressor and a new accumulator (with filter) and spent a full day flushing the condenser, and evaporator and replacing all the parts we bought. I worked and 3 months later is STILL working. It was NOT the easiest repair, but also not the hardest. Expensive to do at a vendor, but should work. It it possible your mechanics missed several leaks (like the ones I faced)?
good luck
-Chris

 

So.. not sure if a '12 is close to an '02, but I had similar issues on mine... had AC system checked and recharged, 2 days later, same thing, was cool, but not cold, usually when coming to a stop or slowing down.
took it back to shop, they showed me how to remove the shim behind the AC compressor clutch, told me they start wearing and the gap gets to large, loses pressure, gets warm, that was in June I think.. been blowing cold since.

 

I've heard about this "shim"....my compressor clutch engages, so could that still be the problem?

 

Might be your blend door isn't closing all the way and letting to much fresh air in, but as stated before yo should either put gauges on it or get forscan to read the pid. Did you check your hepa filter ?

 

My clutch still was engaging, but from my understanding, there was leakage past it, it stayed cold 80ish% of the time...

 

.....There's a HEPA filter?

In case I didn't mention it in the OP...there is plenty of air flow and if I turn the temperature ****, I can feel it go from hot to cold (cool)....

 

Definitely going to look into this when the weather cools down a bit....we've had a heat wave for the past week.
Thing is...it doesn't go from cold(cool) to warm when I slow down....it just doesn't get cold.

 

Don't have a thermometer....but I would venture a guess that it is (maybe) about 10 deg cooler than outside air...when it's cooler outside, the airflow "feels" colder than when it's 80 or 90 deg. outside the cab.

 

Most newer vehicles have a hepa (Cabin) filter behind or under the glovebox area,
As for the temp ****, my old 97 F250 did the same thing, went from hot to cool but not cold and it turned out to be the blend door wasn't closing all the way to let the cold air through it was still mixing with the warmer air. It's a big jump from 97 to 2012, so I'm pretty sure yours is electronically controlled.
But as was said before, you best bet is to put a set of gauges on it and forscan, other than that everything else is a guessing game.