Tripac apu problem

Hi, i have a tripac apu. My heater was not kicking on, the apu was runing but no air was coming from the spar heater. after a while a decided to reprogram my display so it will show me internal temperature.
And there was my problem. Even that is was very cold inside my truck, the display show is was 125 degrees inside. my heater was set to 90 degrees.
My question. How can i reset the thermostat inside my truck?

 

I found the problem i program it to optional control temperature.

 

Sure it's 125 degrees inside, you in Miami.

 

hi my apu comes on just blows cold air .is there a valve in need to on plz help froozeeeeee in mi

 

You sure have it on heat?
I got the system explained once from a TK tech.
For the heater, you set the temp on the display. But the heater has the tempsensor internal and reacts when the temp drops below set temp and fires up.

The A/C has no internal sensor. It's the little pin on the display.