Why go through all that. Just get the arp device with 2 fans. The fans simply zip tie to the removable exterior grills (one low and one high) Its all 12 volts. Protects the fridge from ever overheating causing a fire. Works weather you have shore power or not. The fans are thermostatically controlled to come on when needed.
FYI in some cases, with the fridge in installed on an angle, it may have to be removed to install the arp device. I think this situation is rare.

My OEM fans do not work well in hot temps. Did a mod by adding two fans in the fridge bottom vent compartment. Works great. Plugged the 110 into the outlet fridge is plugged.