For just one side of your interior lights not working, it is likely a damaged wire or maybe a switch that is connecting the lights on one side has failed. You'll need to test the wires coming out of your switches with Circuit Tester # PTW2979.
If the switch is bad and needs to be replaced I have added a link below to our selection of rocker switches for you. view full answer...
There are direct replacements you can get if you let me know the size, make and model of your current roof vent; otherwise, you can just use a universal replacement cover which will work with any roof vent on the market.
For a universal roof vent we have the MaxxAir UniMaxx Universal Replacement Lid for RV and Trailer Roof Vent # MA00-335001 for translucent white or # MA00-335002 for black. view full answer...