Prostar heater core shut off location

Wow, I would call the dudes that know the truck. They like to hide stuff from drivers. Trust Me. Company truck. Oh it is your truck, makes your living. Unless you want to drive someone elses truck & they drive your car. Sorry, your window was down, it rained. It's not my car. Your a driver, act like one.

 

Many of your modern trucks don't have heater hose cut off spigots. They are set up like a car with a blend door under the dash usually on the passenger side. The actuator valve can be broken or some other problem.
If it had a spigot it would be on the passenger side. Follow the heater hoses off the firewall is the easiest way to locate one.

You might not care to fix it but it's your job to at least write it up on the inspection report. Evidently the other driver has the same mentality. Today's defrost systems cycle the AC compressor to help remove moisture from your windows even on warm and the AC off. So it is a safety feature too and not just comfort.

Is the AC cutting off or is the blower motor that stops blowing? Two different lines of possible problems.

 

I look under that hood every day. At least I say I do. Every wire, very hose, every part. Don't know what it does, but I make it a point to find out. Drove a White 4000 2 days before I called and asked why I was baking. 4 minutes, and I was happy. Turn two knobs. We will never know everthing. But we get close.

 

Passenger side of the motor, behind and above the turbo. Good luck reaching them on an aero truck...if they're even there. El-cheapo fleet spec trucks are seeming not to have the valves a lot of times.

 

a/c shuts off as soon as the truck starts up.

blowing warm.

sounds like it hardly has any freon to keep the a/c running.

 

The ProStar HVAC system is computer controlled. Most likely a Thermistor in the AC system or expansion valve.

I had the same problem and it will blow hot air with the AC not working and on my ISX there is no water shut off.