I bought a 2007 Mazda3 last year. After a few months i started getting an intermittent problem where my factory radio/cd player, interior dome lights and keyfob lock/unlock would stop working after the car had run for a while. they would flicker for a few minutes then go dark. After a few hours they would come back on and start over. The trip meter would also reset. After a few months it shut off permanently. Now no radio or interior lights, FOB, the trip meter resets randomly and the gas gauge doesn't work right. I've checked all fuses and none are bad. There is a square black breaker in the engine that has a little white dot on top. an identical one above it has a little window with a black dot. I have no idea if that means anything. Thanks for any help.

 

I'm guessing you need a replacement BCM/GEM/PJB.