Welcome to the class a section instead of around the campfire. It would help if we could find what class A you have. I'll guess it's a gas class A. Are the lights that do not work on their own switch or are they on a switch that operates both sides of the ceiling lights. If on their own switch you need to find that noisy thing that makes 12 V power and next to it is a fuse panel with the little plug-in Spade fuses. One of those imay be blown . If the light share a common switch then you have a loose wire hopefully at the switch.
My two word answer is: Good luck.