Mysterious Electrical problem (interesting)

[chasgrips45]

HEY JEAN, YOU AROUND! Anyway,I`m tooling along 75 r90s,running nice ride ,then FOoOF.......,nothing from engine ,to air compressor
. That machine quit. I looked around ,gas ok etc etc. Now I figure I`ve got to pull the front cover . Now this is on Route 64 in Western N.C. I`m on a bad downward slope,Harley Heaven . Touring bikes all over the area,staring as they pass by
! Sure enough As I`m trying to get the front cover off ,the 10mm nut holding the advance bounces out, Hello. the rotor is off,but this one also ate the black going to the points. I was out there for 2 hrs trying to make some kind of connection in those wires. It`s pretty distracting ,when you`re trying to do patch work on the side of the road ,& semis are going by ,& all the motorcycle riders stare as they wiz by. Got her running ,no front cover ,it`s getting dark ,& I now have the dexterity of a 3 month old golden Retriever. I left the horn wires loose also (I needed to take the horn off) . I made sure they didn`t touch. I `m driving along & notice that every time I hit the front or rear brake,the gen light would glow ,& the voltmeter would take a dive to minus .It`s an old gage so that needle hit the stop at at E=Mc2 ! My bike uses the funky black white ,& some other color wiring to the horn(I haven`t doped out that strange wiring arrangement yet) GSPD told me last year, "just plug the friggin wires in ,if there`s 12v, & ground, the friggin horn will work Charlie"!!! Got home &I by this time had no dash lights ,but it would crank, I noticed by this time that the gen light was on dimly. I hooked up the horn again,& replaced the top fuse that had blown itself out. Everything works ,brake lights ,no short ,horn, the whole works. Is it possible that the disconnected horn wires caused this royal pain in the ass? I `ve got to have damaged something? Any Ideas? BTW through all this ,the clock never stopped working,but the time was wrong!

[Major Softie]

Well, you can damage the diode board taking the front cover off with the battery connected. That fits everything except it all being fine now.

[Deleted User 61]

Did you get any sparks when you removed the front cover?


Airhead ownership 101

* Disconnect battery before removing front cover.

* Block the front of the crank before removing the flywheel.

[chasgrips45]

I forgot to say that I disconnected ground before I took cover off Sorry

[Jean]

In spite of the title "mysterious", it seems it wasn't a mystery once you discovered the nut had come loose all by itself. Lucky you found it. (You needed some luck, there!!)
Yep. I'm here.
gspd is't totally wrong about "connect the wire..." but things like horns DO draw a considerable current and if you make an error with a small gauge wire, it'll be toast pretty quick.
At least you were able to get off the road.
I'll have to read and probably print your total post to figure out what nice words to lay on you next.

[Airbear]

Hmm, can't help with the mystery, but am troubled by the story about bikes whizzing by and not stopping. Here in Oz, if you are crouched on the side of the road looking at your engine, almost everyone will stop. Farmers are particularly good value. They know everything about everything. They'll give you fuel, or take you and your bike home and feed you, let you use their tools, put you up for days if necessary. Does this not happen where you are? What the hell is wrong with this world?

ps: Good luck with sorting the mystery. I'll watch with interest.

[SteveD]

Hmm, can't help with the mystery, but am troubled by the story about bikes whizzing by and not stopping. ....ps: Good luck with sorting the mystery. I'll watch with interest.

That also seemed strange to me.

[gspd]

... replaced the top fuse that had blown itself out. Everything works

The black wire in question has 12V from the coil negative, via the condenser.
it was probably momentarily shorted to ground by the loose rotor,
it is also shorted to ground in everyday use when the points are closed and the ignition is on,
it's no big deal,
but it does suck a lot of power from the system, your coils were getting toasty warm while your battery voltage was slowly dropping.
How long was it from when the engine quit until you actually switched off the ignition?

It wasn't good to have your ignition on and listen to the radio for extended periods in old cars with points.
That's why they eventually added the 'accessory' position to car ignition switches.

The GEN light being on dim could have simply been because the battery voltage was too low when you added the brake light draw, and it needed to charge up.

Do you have add-on fuses or are they OE?
I'd pull out the one that blew and see what works and what doesn't work,
ditto for the other fuse.
that might provide some clues.
it's a lot easier to learn now at home than on the side of the road.

[Jean]

I'm somewhat surprized that NO-ONE stopped either...that is not good news. It sounds like you were on the 4-lane part of 64 that runs west of Franklin...
OK backto the electrical commentary.
As I recall, your bike was somewhat imaginatively wired at our last discussion.
If not too much was changed, I'd venture that when the loose nut took-out the points wire, the fuse blew. Can't be SURE about this tho, as the wiring might not be arranged as I imagine. If that circuit hasn't been messed-with, the lead to the points-thru the coils- uses the fuse terminal as a connection point.
When you apply the brakes, the voltmeter will normally dive to small numbers as the headlight/taillight is probably on, and the brakelite makes a good load. (higher wattage than the taillight)
Now that you have replaced the fuse, and properly tightened the little nut...does everything WORK? As in, when you turn the switch ON, the charge-light lights, then when the engine starts and revs to around 3000, the light goes out? OUT, NOT glowing dimly...glowing dimly could mean you damaged your diode-board...maybe took out a phase...or you may have some burned insulation someplace.

[30yearoldjunk]

Hmm, can't help with the mystery, but am troubled by the story about bikes whizzing by and not stopping. Here in Oz, if you are crouched on the side of the road looking at your engine, almost everyone will stop. Farmers are particularly good value. They know everything about everything. They'll give you fuel, or take you and your bike home and feed you, let you use their tools, put you up for days if necessary. Does this not happen where you are? What the hell is wrong with this world?

ps: Good luck with sorting the mystery. I'll watch with interest.

Oz sounds like old-timey Texas. Lots of us around here dream of visiting there.