On my old Dometic AC, the freeze sensor was clipped to one of the copper coil tubes. I learned through trial and error that the sensor was ok, but the contact between the bracket and the coil would become corroded from all the moisture. When it made bad contact, every dozen trips or so, all I had to do was reach up there and move it around to clear the corroded metal, and it would once again keep the compressor from remaining on too long and avoiding the freeze. I also learned that if the warm return air is pushed through the coil too slowly, like when your duct outlet deflectors were turned down too much (leaving too small an outlet space), the warm air moves through too slowly, and allows the coil to freeze much easier. This is especially true in humid conditions, for obvious reasons.
2006 Jayco Seneca 34SS
2006 Jeep Wrangler Unlimited Rubicon Toad