I have a Norcold 1200RIM. Every time I drove thru a rainstorm, that red light would come on and the switch would activate and shut down the fridge. I would have to get the hair dryer and dry off the switch and then take a magnet and reset it.
Then came the day it would not reset. I was on my way home from a 2 month summer trip, the weather was hot, so I decided to just by pass the switch so I could get the fridge working again. I of course, can not recommend you do this, but it is a simple process and it can get you working again.
When I got home I ordered the 110 volt HVAC cooling unit from JC refrigeration. No more fridge problems and the Norcold works like a residential unit.