The switch is mounted on the tubing at the end of the finned radiator at the top rear of the fridge. The AS part number is 690394 "Power ventilator, refrigerator". I assume this is the fan and the sensor since the sensor isn't separately listed.
I'm just as happy with the toggle switch inside the trailer that I had on my previous trailers.
John W. Irwin
2005 Classic 28 "Sabre-Dog III"
2013 Silverado 2500HD Duramax/Allison LTZ
WBCCI #9632, TAC TX-10