If set on Auto, it will run at hi speed and when it gets within about 3 to 5 degrees of set temp, it goes to LO speed. If left ON once it reaches the set temp the compressor AND fan will then shut off. Doug
From the Zone tstat manual. Link to your manual.
https://www.intechtrailers.com/images/info/PDF/Dometic/operation-manual.pdfAuto Fan
When auto fan is selected the fan speed will vary depending on the
difference between the temperature set-point and the room temperature. In auto fan the compressor and fan cycle On and Off with the
thermostat.
When the difference is:
>5ยบ The fan operates on HIGH
<4ยบ The fan operates on LOW