Today I turned off my car's engine and left my radio on while loading something into it for less than 2 minutes. When I restarted the engine, the radio turned off briefly like expected but didn't turn back on. After driving for 5 minutes or so, the radio turned on by itself then turned off again. Please advise what to do next. Where do I find the radio fuse? (Unfortunately I do not have the owners manual.) If fuse isn't blown what's the next step?