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...
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...