Hi all, hoping you can help me here. I have a 2012 Chevy Express 3500 15 passenger van. All of my map lights and the radio back light stopped working at the same time. I've checked every fuse I can think of and they're all good. Any suggestions?

 

grab schematics from gmupfitter.com and probe for faults

 

Checked the "hidden" button above the dimmer? Dimmer turned full dark? Either way that switch is one spot where those 2 things exist together.