He'd find out pretty fast when the R134a manifold set connectors don't fit. R1234yf (the latest alphabet soup automotive refrigerant) systems use different connectors.

 

I don't think there is anything wrong with the truck, it seems to be user error. The system doesn't have the capacity to cool fresh air when the outside temp is in the mid 90's it should stay on recirc. The system is programmed to automatically turn on recirc at 75+ just for this reason. On fresh air, you're asking the system to cool and dehumidify the 90+ degree outside air. On recirc it's cooling the already cooled and dehumidified air in the cabin by running it back through the evaporator.

 

I know, but my brain refuses to register properly.

What year did the F150's switch to yf? I kept getting told I had a constantly variable compressor when I was inspecting my a/c in 2019, but no, it's an on/off compressor, and the manifold set I bought to work on my 95 SHO fit the truck and it takes the old refrigerant.

 

I leave mine on recerc all summer long.

 

I did not know, obviously, that they had switched to YF that early!

 

Short answer for the F150 - 2017 (except Raptor - 2021).

Download "official" Ford charts from this page: https://www.fcsdchemicalsandlubrican...eferencecharts

EVDC compressors first appeared on the F150s beginning with the 2017 3.5 EB (only). For 2018, all F150 engines except the 3.3L used the EVDC.

 

I'm used to not having to use Recirc and having to turn it down or look for a sweater.

It has cooled down here but it still doesn't seem to be working as well as it once did.
The air coming out the vents doesn't seem to be as cold and seems moist like its not drying the air even at 85.

 

Mine does, once the interior is cooled down. With recent temps 100+ every afternoon, I start the vehicle on Max AC, then when it's cool I switch back to Auto (and Recirc usually turns itself off at this point). Auto without recirc is capable of keeping my truck comfortably cool (68-70 degrees). If AC performance seems to have decreased, I'd clean the condenser, ensure the cabin air filter is clean (and not a HEPA model, which reduces airflow), then have the AC serviced. Recirc certainly helps, especially on sunny days.

UPDATE: Confirmed today in 92 degree weather that my AC doesn't automatically turn on Recirc. Auto without Recirc cooled the truck just fine.

 

Confirmed today in 106 degree heat - Recirc turns on automatically only with Max AC. When switching from Max back to Auto, recirc turns off. While in Auto mode, Recirc stays in the last position I left it.

 

My 2018 5L xlt Screw has manual climate control >> except for remote starts when it can be selected two ways or OFF, how it is handled under remote start conditions.
I have it selected as the last climate setting for A/C and cuts back after drive-off.
When I remote start, the A/C goes near full on, cools the interior and the engine idle raises up to near 1000 +/- rpm to force the cooling to perform faster, then returns back to normal idle.
When I drive off, the system warms up to a more normal cooling level it decides on.
The A/C system is variable efficiency that does this by program and sensor control.
If not cool enough after driving off, I can set for more or less cooling as desired.
Can there be a problem? Sure, but it needs to be known how the system is supposed to work as fault free, before that judgement is made.
Good luck.