My TT Dometic refrigerator started acting erratic. Could not be trusted unwatched all night. Status lights would be odd combinations. Flipping the vent fan switch could give it fits. It was glitching the control board.
So whats up? Well it's a long way to the battery. The Dometic control board has very little capacitance on it's power input.
My fan upgrade contributed to the problem. A pair of IP67 PWM 140mm and a PWM control board which has 100uf cap on it's input. That's not much, but the turn-on charge surge enough to glitch down the power line.
I fixed it by wiring a car audio power line filter to the control board and fans.
Do not wire it to the DC heater, the difference in wire gauge should be a clue.
The power line filters typically have 1000-2200uf caps and a ferrite choke rated 8-12amps. Open it up and read the capacitor voltage. You want 25V or higher. 16V is not high enough for RV charger doing an "Equalization Charge".
Noctua NF-A14 iPPC-2000 IP67 PWM, 140mm 4-Pin Heavy Duty Cooling Fan with 2000RPM and IP67 (Black)
ELEGIANT DC 12V PWM PC CPU Temperature Controller Board - 4 Wires Fan Speed Controller with High-Temp Alarm. Comment for 2 fans a standard splitter cable is needed. NO LINK: Other Amazon vendors carry same thing.
Noise Filter BOSS Audio B15N for Car Audio Systems. Comment: Easy to mount but I felt compelled to replace the 16V cap with a 25v one.
Asdomo DC 12V Pre-wired Black Plastic Audio Power Jacks Noise Filter Ground Loop Isolator Suppressor for Car. Comment: Crack it open, cement it back together. No mounting ears.