TT, according to the manual I connect to the green wire, and test the three yellow leads (I believe those are the diodes, at least that's what the wiring diagram in the Clymer says.) Then reverse the lead positions, test again, that's six tests. Then do the same with the Red/White wire. Please correct me if I am wrong but I believe that is the 12 tests you are referring to, which I performed and found the resistance to be nearly a third of what Scunny found when he tested his. Could this be pointing to a toasted RR?
No, your rectifier section is testing good, from what I can tell. The diodes all conduct in one direction only. When you reported measuring nothing, I assume you mean to report zero resistance. Zero resistance is like a straight piece of wire, and 4.5M Ω effectively blocks nearly all current flow. Ohm's law I = E/R. 0.0000027 amps is not much to worry about, as the battery will self-discharge faster than any leakage through the diodes.
So to test the regulator I need to have the bike running and put the probes on the green and black wires coming out of the RR? Would this test the voltage coming from the alternator unit? Sorry, I'm just starting my shift at work so I don't have my manual to reference the wiring diagram.
The Green and Black wires are power going IN to the Regulator. The Vreg also uses these wires to sense the battery voltage.
The Black and White wires going to the alternator is power going OUT to the alternator rotor from the Vreg. The voltage level on these wires is how regulator controls alternator output. This B/W voltage is maxed to peak when the sense voltage goes below a trip level measured from the Black and Green wires. The trip level is probably something like 12.5V or so. So, if the black and green wires are below 12.5v, then the regulator puts what voltage it receives on the Black and White wires to the alternator. As the sense voltage gets near 14.5V, the Vreg lowers the voltage on the black and white wires, which reduces the output of the alternator (so it won't overcharge and cook the battery).
This is roughly how it should work. Exact trip points and output voltage levels I don't know about this specific unit. I do know what the battery requires and how it relates to controlling the alternator. AFAIK, no one on this forum has posted a relationship chart between Vreg sense voltage and B/W output control voltage.
Bear in mind the alternator puts out variable power with RPM (which is why a Vreg is needed), so it can reduce its output power when it is making too much (assuming a good alternator).
In circuit testing requires the circuit components be connected together. The meter probe simply monitor what voltage exists where in the circuit.
A temporary bypass test can be made to help isolate the circuit fault. Disconnect, the black and white wires that go to the alternator from the R/R at the R/R. You can jumper the power direct from the battery to the Black and White rotor wires. This should make the alternator be all it can be, and revving the engine should get you battery voltages 14.5V or above, assuming the battery is at full charge. Just like you can't (shouldn't) deplete a battery instantly, neither can you charge a battery instantly. You don't want the battery voltage to linger above 14.7 V. So, if you begin to monitor that, stop revving the alternator, as you have proven it works fine under this vreg bypass test.
I assume you understand the rectifier still needs to have all its connections made. All yellows, the Green, and the Red must be connected in circuit, as that is what convert the AC power from the alternator to DC power that the battery can use.
Questions?
TT, so just thinking, if my rotor is testing at say 4 ohms (taking into account the variance from the tester and it's weird fluctuations) that makes it 3 amps going to the RR. Would that be enough to cause the RR to go bad? Is it possible the RR is still ok, or is it now toasted, so I need to get the Rotor rewound in addition to replacing the RR?
I don't know where the output current damage level occurs for the current handling device inside the R/R. It has a rating/spec from the factory where it was made. But, like the V rating on tires, it may survive going over it's limit for some period of time. But, double the input conditions and it is likely to fail pretty soon. The answer to your question lies somewhere in between.
The in-circuit test, or the bypass test noted above will provide better info about the vreg's current operational state.
The rotor cannot be rewound Brandon, it's some kind of lump of metal!
From what I have learned the 650 rotor CAN be rewound/restored. Its' the 750, 550, 500, 350, 400 Cbs that have a slotted metal rotor.
Cheers,
