I was driving and my radio, dash light, headlights, brakelights, interior light, lock/unlock switches all stopped working. I checked the glovebox fuses and they didn’t help. GM didn’t label the relay boxes on the engine so I can’t tell which is ACC, if that’s even the problem. Help!
For everything to stop functioning all at once it sounds like a ground problem. At the very least the radio and interior lights are typically on different curcuits- you may want to pick up one of the chilton manuals to try to identify where your ground is installed-it may have loosened up or wires may be frayed.
Time to buy a service manual. Try Books4Cars.com. No, I’m not an employee, just a satisfied customer.
In the meantime, I’d be checking the main electrical panel under the hood. Sounds like a fusible link burned out, or some other main component.
I hope you’re not driving this vehicle with all these important things not working.