2010 Lonestar AC Issue

[Waterloo]

If you are outside in the sun working on the AC, and do not have that heater core off, you are not going to get AC. The other thing I did was to dig the outside ambient air temp sensor out from under the radiator and get it to some fresh air. I moved mine all the way up to the windshield wiper cowl. It does connect to your AC system, I discovered that on my own while troubleshooting something else with Body Builder.

Do those two things and you will freeze yourself out of the cab. I have been running down around I-40 and by noon I have to turn the heat on. I also installed three fans in the truck, Yacht fans, boating... One under the overhead, two in the back corners of the sleeper blowing the cold air out of the sleeper up front to the cab. It gets painfully cold in the cab now.

Here are the fans...

Caframo Ultimate. 12V Lighter Plug Fan for Boats and Campers. Easy to Clean. White
https://amzn.to/2HhY16N

And here is Body Builder, you will find your truck a few lines down...
http://bodybuilder.navistar.com/General/BBcircuitIX.htm

That temp sensor is under the radiator in the harness, driver side, under around ten yards of tape. It has a clip on it and a little bulb, two yellow wires on mine. About the size of your thumb. Just get it away from the radiator and engine heat. Your AC will thank you. And install this valve,

Motorized Ball Valve- 1/2" Brass Ball Valve with Full Port, 9-24V DC and 2 Wire Reverse Polarity by U.S. Solid
https://amzn.to/2KPb4gI

Here is the switch you will need to operate it.

ESUPPORT Car Univeral Heavy Duty 20A 125V DPDT 6P On/Off/On Rocker Toggle Switch
https://amzn.to/31KaiZk

If you install fans, here are the remote controls I use, you will want these if you go the full monty on the AC...

DONJON Wireless Remote Switch with 328ft Long Range DC 12V/24v/48v/72V Switch
https://amzn.to/2HeYuqn