This week, i spent two very-near-100 degree days at a state park with afternoon sun on the refrigerator-side of my AI. At departure, I had turned off the freezer since it was empty. I thought that might help the refrigerator.
The first day out, the refrigerator temperature was all over the place. I even pulled out the drip pan and rigged a fan to try to keep it cold. It stayed too warm until the sun faded.
That evening, I turned on the freezer. With nothing else changed, the fridge temperature held quite well all through the second day. It went up from 33 to 37 at mid-afternoon.
I think there may not be very much insulation between freezer and refrigerator section. The freezer being on may also have added enough heat to improve the adiabatic flow over the coils. I learned my lesson and the freezer will now stay on.
There is not a good place in the refrigerator to tap off 12v
. I'll either use my old battery fan or use a flat wire pair to power a muffin fan from now on.