Motorcycle Questions? Ask a Mechanic.
Hi and welcome to JustAnswer, I’m Louie. Sorry you had to wait awhile but I’ll do my best to help.
Initially, is a standalone volt/multi-meter available?
Let's try check and review the basics. Proposed preliminary tries (if have not been done):
In most instances, it would be a regulator that has failed.
However, if left unchecked and over time, the stator gets cooked causing a short to ground with any of the 3 or all of its windings.
The end result would be a replacement of the stator and regulator combo.
The regulator would still be a suspect then.
Also and even if just for test purposes, consider hardwiring a secondary ground line from the battery's - terminal to the frame, then also to the engine and to the harness ground/black wires.
And perhaps the article HERE may provide insight.
Very significant findings!
In both cases:
...were the stator wires connected to the regulator?
Can you please provide clear closeup pictures of:
Appreciate the pictures.And would appear several connectors? ...extension wires?Let's go back and re-trace our steps/checks:
To ensure that the readings are taken from the wires themselves and not at the pins/terminals of the connectors, carefully use safety pins as extensions of the multi-meter test probes to be able to puncture the wire insulation.
I understand; when able.
Actually, I am inclined to suspect:
If there is a resulting over heating of the wire(s) and/or connector/terminals, then yes to the further investigation.
However, if the heating up is normal (you can still touch/hold), then should/would be acceptable
would again point to a stator issue.
...the alternative is a failing alternator rotor. Item # 1 HERE.
"... disconenct the stator though, the AC voltage is what you would expect..." = 'ghost' or technically, no-load voltage.
The regulator was ruled out since:
could still touch it;
when hot/not charging...three (3) yellow wires directly to the regulator = __11__ACV hence too low already at its input, therefore/expectedly the output would also be low.
By process of elimination and more importantly "...hot/not charging...stator...AC Voltage... = __11__ACV...", then stator and/or rotor are the only suspects left.
As posted, no-load voltage; i.e. a condition when there is 0 current flow and the voltage would tend to go up.
This is a universal constant condition. Technically and if mathematically interested, part of Thevenin's Theorem. Please click HERE.
By process of elimination, that would leave us just with the rotor.
Yes, not that often.
Known causes would be if dropped and/or if there a cracks no matter how small.
Compare its magnetic strength with a known good rotor
...or better yet, swap even if just for test purposes.
Have not tried that approach. , But if ever, aside from the 3 stator wires, engine/frame/battery ground wire would have to be hooked up as well.
And yes, it may be simpler/easier to connect the Triple's regulator to another motorcycle with known good stator output.