QuestionHI! I've got a 1972 Honda CB500. Has been running great since I bought it (8 months). Today I was riding when the wiring harness holding the 4 bulbs (flash, neutral, oil, beam) fell out from the handle bars. Continued to run fine until about 20 minutes later I was turning a corner and the bike died (not sure if the issues are related). The bike wouldnt even turn over (that is why I am assuming an electrical problem). Not very well versed in this area, any ideas?
AnswerJon-Michael,
Go to an auto parts store and buy a cheap $5 12v test light with probe end and ground wire so you can do effective testing, if you don't have one already.
Check your fuses first. Refit the 4 bulbs and harness back in place.
It sounds like you blew the main fuse, perhaps. It is back by the battery under the side cover.. left side, as I recall.
Check the wires coming out of the ignition switch. I think your switch was mounted under the gas tank on the left side. Some were relocated up to the handlebars with an accessory bracket. That kind of stretches the wiring and sometimes the wires unsolder/break themselves from the switch base.
Make sure your battery is fully charged. Test light should light up bright across the battery terminals. Then check the fuse, by grounding the probe wire and probing both sides of the fuse/fuse holder connectors. If you have power on one side and not the other, then the fuse has blown.
If you replace it and it immediately blows again, then you have a dead short in the + side of the wiring somewhere. You may need to remove the seat and fuel tank so you can access all the wiring harness connectors from front to rear. Make sure all connections are shiny and tight.
http://www.oldmanhonda.com/MC/WiringDiagrams/MCwiring.php#class for wiring diagram.
Bill Silver
