Tripac APU Code 49. Restricted air flow.

Symptoms: when running AC the air is not cold. Code 49.

When you hook up computer and diagnose it code 49 usually comes with several other codes. Also on 1st page (Dash Board) Cabin Temp will show unreal temp, mine was 155 degrees. 

The air flow sensor on the control panel (inside the cab) is broken. It's a small black plastic pin at the bottom of the panel.
You need to replace the control panel as it's usually wiring behind the sensor that is bad (which is hard to see). Use medium flat scredriver two pry two latches at the bottom of the panel and then disconnect the cable inside. Cut zip ties on the cable inside the cabinet and this will make the cable longer and easier to unplug/plug).

Or, if you like me and don't have another control board laying around, you can just replace the sensor, easy job if you ever hold soldering iron in your hands. Sensor is just a 10k thermistor. Just cut off wires from old sensor and remove it, make sure the ends will not short anything, and solder the new thermistor as seen on a pic below.