There are two positions on the fan control. One is on and one is automatic. You can turn the fan on, or you can set the control switch to auto and set the thermostat to the desired temperature inside the coach and when that temperature is reached the fan will turn on. It will then exhaust the warm air until a lower temperature is reached and will then turn off. Works just like a whole house fan or attic fan on a house.
RognBon
1997 Monaco Dynasty 40'
Cummins 8.3 325 HP
2008 Ford Edge Toad