To my knowledge (I am sure someone will clarify if I am mistaken), your fridge should run the same on AC power as propane but it is possible to be a bit warmer. As long as the freezer is still getting cold enough to freeze and the main compartment is keeping cool.
When you say its a 3 way, I would assume it is a model that runs on AC, propane and when traveling, is capable of running on 12volts DC. Usually, when the running on the DC circuit they do run at a minimum chill level so they will be warmer than when running on propane or AC current. Also when running on 12V they will only run for about 20 to 30 minutes on battery when not hooked up to the TV with the engine running. This is to save the TT and TV battery.
I have replaced several refrigerators in TT's, Campers, and MH's (most due to age). I will tell you this about the three way refers. DO NOT get the circuit board wet while the refrigerator is running. That mistake cost me.....
2015 White Hawk 25BHS Glacier Package
2004 Dodge Ram 2500, 5.7 Hemi, 5Spd Manual
2008 Arctic Cat M1000 SnoPro
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