One day I was driving & suddenly all my interior electrical just died. I have no tail/brake lights, interior lights, radio, locks, windows, fan, clock, dash lights. Only things that work is headlights, signal lights, wipers, & horn. I checked all the fuses in the center dash & even changed the relay that's the main power & still nothing. I checked under the hood & checked the box next to the battery & all is good. The funny thing is I can turn on the A/C & the compressor comes on but the blower won't. I didn't change the big black relay under the dash & don't know how to check that. Could that be it or something else? I hope someone can help me figure this out. I can't drive it because now it's unsafe with no parking/brake lights. Thanks.