Adding computer fan to City water hookup port. Here are pictures of my construction of the project.
Switches for External Ventilation Fan (upper) and Circulation Fan, inside fridge (lower) with power-on light.
In place of the A/C switches I've placed a volt meter for my main battery and a USB plug, connected to the cigarette lighter plug, with a switch below to de-power it when not needed.
In the process of adding this second voltmeter, USB plug and cigarette lighter socket beside rear closet. This will be switched as well and connected to the Aux Batter.