ground

Hello, while I’m new to posting I am a veteran lurker. I have previously owned a 79 but unfortunately had to sell. I now own a rather troublesome 81. When I first bought the bike it was completely stock apart from the missing battery box. The original ignition black box was shot so I fiddled...

The main fuse keeps blowing(twice). I figure I've lost ground somewhere on one of the handlebar switches. How and where can this happen and what is the procedure to test? Manuals are a little tricky to understand for using a multimeter. Any detailed instructions would be appreciated.

I am doing some troubleshooting on my bike after lots of parts swaps. I am curious about something, what is the primary method that the engine is grounded back to the frame? I am having some issues starting the bike and I am thinking this may be the culprit. Is it grounded simply by the...