Before I dig back into this next week with some help, I thought I would see what ideas folks might have.
I changed out the battery in my "72 SWB 75/5. Hooked the cables back up and the high beam came on. Ignition was off. I had pulled the tank, so looked for pinched wiring along the frame, but all looks kosher. IÂ had moved the subframe back about a 1/2-inch, but don't think that disturbed anything either.
I'm thinking maybe it was just a coincidental failure of something like the ignition switch/nail thingy. Pulled the head lamp. I have a wiring diagram, but I'm not very smart. On the ignition switch, I checked for continuity between the red wire terminal (source of 12 V, I figured) and the brown wire terminal (ground) with the key out. I got continuity. Should that happen? Seems like everything in there should be disconnected with the key out.
 Or, better question, what might I have done to my bike to cause this? And what/how do I take the next step in diagnosing this?
Thanks in advance!
I changed out the battery in my "72 SWB 75/5. Hooked the cables back up and the high beam came on. Ignition was off. I had pulled the tank, so looked for pinched wiring along the frame, but all looks kosher. I had moved the subframe back about a 1/2-inch, but don't think that disturbed anything either.
I'm thinking maybe it was just a coincidental failure of something like the ignition switch/nail thingy. Pulled the head lamp. I have a wiring diagram, but I'm not very smart.Â
Or, better question, what might I have done to my bike to cause this? And what/how do I take the next step in diagnosing this?
* That is indeed strange. Are you sure the "nail" hasn't simply been removed in the headlamp ON position ?
* Your issue has to be somewhere within the headlamp-mounted ignition/HL switch, the wires going up to the bar switch, or within the bar switch itself. You almost certainly have a mechanical or water connection between the RED terminal and those that power the headlamp circuit. Inside the "nail switch" is the most likely location because the RED and HL wiring are both present there.
* Any RED wire is directly connected to the battery. No fuse. No cutoff switch. IOW, it's always powered ON.
On the ignition switch, I checked for continuity between the red wire terminal (source of 12 V, I figured) and the brown wire terminal (ground) with the key out. I got continuity. Should that happen? Seems like everything in there should be disconnected with the key out.
Red goes directly to the Pos battery terminal, and Brown goes directly to the Neg battery terminal. I believe you are simply reading the /5's battery voltage. You should always get 12 volts between those 2 terminals (Power & Ground). Your continuity tester is nothing but a voltmeter and is probably powered by an internal 9V battery.Â
I think you should put the continuity tester down. It's the wrong tool for this job and a big motorcycle battery won't have any trouble frying the tiny circuitry designed for a 9V battery.
Get yourself a "mechanic's test lamp" like this...
Owning an old Airhead is easy.
Keeping an old Airhead running great is the true test.
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