Thanks for the excellent information. Sorry to barge in, but you sound like you know the electrical system like the back of your hand.
My '89 GL1500 has an odd starting issue. I believe it is electrical. I turn on the ignition switch and press the starter button. The engine cranks over nicely, but it doesn't fire up until I release the starter button. Therefore if I crank it for 2 seconds, then release the button it starts. OR if I let it crank for 5 seconds or even longer, it only fires when I release the button. Not always, but usually.
My theory is that there is insufficient voltage getting to the coils while the starter motor is cranking. Then when the cranking stops, boom it fires up. Is there some circuit or relay that is failing to supply voltage to the coils?
I did a ride a while back; stopped and shut the ignition switch off; accidentally hit the kill switch when removing my hands from the handlebars, without realizing it. When I came back later, ready to ride, I cranked the bike until the battery was run down. Then discovered the damn switch being off. Arrrrrghhhh!!!! Push started the bike, and it fired off immediately, even with the battery very low. Does this have anything to do with the above delimma. I was surprised at how quickly the bike started. Of course the starter motor was not being used.
Any ideas? Thank you so much.
1989 Honda Goldwing GL1500
1982 Kawasaki KZ750