Prostar A/C blows hot within 30 mins

I have been through everything mentioned here on my ProStar. After three years + I finally have AC in my cab. All of the symptoms you have, I figured it out by accident chasing another electrical issue. Find the Ambient Air Temperature Sensor. I bet it is like mine, in the harness up under the radiator on the driver side of the truck. Dig it out of the harness, dig the two wires out of the harness and relocate that sensor. I clipped it to the windshield wiper cowl where it is exposed to the elements.

Since doing that roughly 4 months ago, I have had AC in my cab. I have replaced everything on the AC system multiple times, hit many shops, thrown well over ten, maybe twenty thousand dollars into this system and it has never worked, until I dug that Ambient Air Temp Sensor out and moved it.

Try that, it is free, just an hour of labor at most.

 

I’ve got a 2015 ProStar did a drop /hook a/c was working fine while on the yard left out n didn’t 10 mls down the road n the a/c was blowing hot air drove for about an hour to nearest truckstop stop to fuel n weigh the wagon n when I got to the end of the exit ramp a/c started blowing cold air again it worked fine while I did all and a 39 minute break but when I got back on the didn’t go 10 mls and a/c started blowing hot air again. Any help wld be very appreciated