They are for the heater in the wet bay under the coach. Turn the switch on and system is armed. when temp falls down to mid 30's, the snap disk switch located in your wet bay will turn the heater on. When the heater is running, the second light on your display will turn red.
I would suggest putting your coach make and model in your signature line. It will help you get information from others.
Bill & Brigitte
06 Windsor PEQ, Cummins 400 ISL
2014 Honda CRV