Baffling slide/electrical issue

I have solved the problem and before you judge me when I state it was only the 30A fuse, please read what happened. First, I have red LED lights next to each fuse which is supposed to glow red when a fuse blows. There was no lit LED light. Second, I measured 11.74 VDC when the problem was first discovered, and still measured this voltage today before troubleshooting. When I discovered there was nearly a volt difference between battery voltage and problem slide switch voltage, I started tracing the problem from the switch which led me to the fuse. So, the moral of the story is a blown fuse can still allow voltage to pass through and those red LED lights don't always work. Now I can only hope the fuse doesn't blow again and expose another problem to diagnosis, plus, I have no idea why my 15A control panel fuse blew twice. Thanks to those who responded with assistance