Case/IH AC issue

[Hay Dude]

My MX270 has a cab with typical AC system, except mine is malfunctioning.
Theres 2 dials. One dial is infinitely adjustable dial for fan strength and one is a mixing dial for hot/cold. The mixing dial just goes from Blue (cold) to red (hot).
Then there’s a 3 position rocker switch. 1st position is AC “on“ all the time, 2nd (middle) is “off“ and 3rd is “automatic”.
When it’s in “automatic“, the more you turn mixing dial to blue, the colder the digital readout number reads and presumably the colder the AC. However, the auto position doesn’t work. Just blows cab air, with no AC.
The 1st position blows very cold AC.
The infinitely adjustable dial for fan strength is either on or off, there’s no adjustability.

Any suggestions on fan speed? Is it a module or resistor not working?
Any suggestions on auto mode not working?

 

[RickB]

The symptoms kind of indicate a resistor failure IF it was a typical AC system with low/med/high fan settings. You are describing a climate control system which is only found on larger more full featured tractors (and motor vehicles). You are probably looking at some type of controller/module failure. Could be a simpler variable rheostat but I bet you won't be that lucky.
SDman or Jim Naden or one of the other red guys over on NewAgTalk might be able to help.