Worn ignition switch, and it's repairable. I just had STick's 223,000 mile switch out last week to complete wiring repairs. Took the entire bottom of the unit apart. There are only three wires on there, red from battery and the red black back to the fuse block plus a blue orange which feeds the fan. When the key is ON, the red is connected to both the other wires. The connector is a spring loaded brass plate above the white plastic disc directly above the rivets to which the wires are soldered on the bottom of the white disc. Notches in the body of the switch provide ramps for the spring loaded balls swing left/right to make contact. Kind'a hard to describe but makes sense when ya have it all apart.
(Side note: I got into mine in Waterloo, IA a couple weeks ago when the bike quit dead. Problem turned out to be a factory defect cold solder joint on the bottom where the wires connect. 3 hours of disassembly/resolder/reassembly got us back on the road. Also got to meet some nice guys at the Salvation Army HQ there, and lunch with Rob Parker, whom I had not seen in a few years.
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Removal: getting to the switch to get it out is a real PITA. To do it right, the following must come off: panniers, seat, side covers, top shelter, air cleaner top and base. All because the connector for the switch is under and in front of the air cleaner base.
To remove the switch itself, two #40 Torx bolts must be removed. They are factory lok-tighted, and torx hole is shallow, easily stripped. AMHIK.
Once out, turn it over and see three small Phillips screw (#1 tip?) which holds a black plastic cap. Once removed, you'll see the solder points for the three wires, red to one side jointed to two rivet, black-red next to it, and blu-orange to another rivet a little closer to center. The white disc can be removed too with a little encouragement. Place a [-]tool[/-] towel on your work surface so ya don't loose any of the small parts. BTW, there's a second set of contacts which are unused in the ST application. Theoretically, the functions could be moved there but expect the wear would be the same.
In my case last Saturday the actual fix involved resoldering (again) the loose joint on the bottom, but while I had it out I took it completely apart and cleaned those moving parts. The fork lock was also not working so cleaned and lube it as well. All it takes is patience, elbow grease, and NOT loosing any of the brass plates, springs, or balls.
Reassembly is reverse. Since all the parts are "keyed", should be impossible to get it wrong.
BBTW, this is the second problem I've had. First was a few years ago (we were in this house so maybe 10 years.) Same problem as you are currently having. Did the remove, disassemble, clean and lube, reassemble. No real serious wear and that "fix" lasted about 70,000 miles. This time, the switch part was working okay but figured, what the heck. I expect it'll last another 50/60K with no further problem.
Another couple side notes: The key code is stamped on the barrel of the switch so if ya lose yur keys, a good locksmith can make more using that code. The torx screws can be a real PITA to get out so initial removal in a comfortable shop might save ya on the road. I was lucky to have access to more tools and help in Waterloo. I also "slotted" those torx screws with a Dremel this time so they will easier to remove should I ever have to again. Gonna do the same on lipSTick and STanley before the need arises.
But here's the real important stuff. The bottom of the switch can be disassembled without removal from the bike. Those three Phillips screws can be reached with the switch in place, and the cover, 'lectrical and contact parts pulled out. The harness is just long enough to let ya pass all those pieces up to clean air next to the right fork on top of the knee panel.
And, most important for on-the-road repair: you can cut the harness a few inches from the bottom of the switch and pull it up top, then strip the ends of the three wires and twist them together to get ya going again. All the lights come on, the bike starts as normal and away ya go. The blu-orange only provides power to the temp sensor so the fan won't run unless needed. At the next town, stop at NAPA and get some crimp connectors and a switch if ya want. This is what we did when my solder job failed the _second_ time in Colorado. Thanks to Uncle Larry and 970 Mike for sticking with me on that one.
Long winded I know, but real info in here for the High Mileage folks amongst us. Suspect all this is true for many Honda bikes and others as well, as the switches are usually pretty simple compared to what they put on our cars 'n trucks these days.
Should'a took pictures.