Rewound Alternator Rotor gouges, trouble shooting charging system.

[gggGary]

Same effect if the black (ground) to the regulator has a problem.

That can be caused by (among other things) an internally corroded battery ground strap.

A story; a now passed on forum member and a good guy had been fighting charging problems for a long time, threw lots of parts at the problem, to no avail. Finally convinced him to bring the bike to TSOIR. Another buddy was here with me when the bike got here. We had the problem isolated, repaired in 20 minutes flat.
Not that I'm a guru, just that electrical problems yield to methodical troubleshooting just like everything else.
It doesn't hurt to have KNOWN GOOD parts to substitute in, along with meters and jumper wires to isolate the issue.
PLEASE do not ruin another rotor (#3)

 

[75XSFLORIDA]

for my own reference;
View attachment 239101

JP Devol has a good point.
Ohm out the main on off (key) switch. a bad, corroded internals main switch can be the problem here.
I've been thinking along those lines for a while now.
The voltage regulator looks at the brown wire to see what it THINKS the battery needs. If that voltage is low it will continue to provide full alternator output to the battery even though the RED wire is at 15 volts and is overcharging the battery.
A high resistance in the ignition switch will make the brown wire read low. It should be within 1/2 volt of the battery voltage.
Corroded contacts in the key switch are VERY common. If it hasn't been rebuilt, cleaned, there is internal resistance there.
The 75 switch is a bit of an oddball has 5 leads the other years have just 3.

Gary, main switch is OEM NOS probably a year old. I had it apart two weeks ago when I first had the problem just to look internally and it’s flawless inside. Bright shiny bear aluminum and you can eat out of it. That’s what startling me about this bike, everything is flawless.

 

[gggGary]

Gary, main switch is OEM NOS probably a year old. I had it apart two weeks ago when I first had the problem just to look internally and it’s flawless inside. Bright shiny bear aluminum and you can eat out of it. That’s what startling me about this bike, everything is flawless.

Your picture is the kill switch (VERY pretty) it has nothing to do with charging, it's not the main switch. I said KEY switch just so you wouldn't confuse it with the "kill" switch.

 

[Jan_P]

Your problem now is 1 of 2 things.
1 a bad regulator or 2 a wiring problem causing the regulator to see a lower voltage then what the battery has.

If we get the correct Info it has been tested with 2 regulators
1 Mechanical
1 New electronic.

Main Switch or Ground
Both can be jumped

 

[75XSFLORIDA]

Your picture is the kill switch (VERY pretty) it has nothing to do with charging, it's not the main switch. I said KEY switch just so you wouldn't confuse it with the "kill" switch.

For some reason I was thinking Kill switch. You’re correct. Lol.

Your picture is the kill switch (VERY pretty) it has nothing to do with charging, it's not the main switch. I said KEY switch just so you wouldn't confuse it with the "kill" switch.

Can you advise me on how to ohms test the ignition switch? I can’t find it anywhere in the manual. Set meter to 200ohms and then what?

 

[GLJ]

Do this test and lets see if the regulator is seeing the same voltage as the battery has.

 

[75XSFLORIDA]

View attachment 239103
Do this test and lets see if the regulator is seeing the same voltage as the battery has.

Yep. Doin that tomorrow. Too late now

 

[jpdevol]

Yep, I only had half the question - GLJ has the complete question: overcharging can be low voltage on the brown (from drop at the switch (etc) per Gary) but also can be a bad ground to the regulator. It's not well discussed in newer manuals, but here's two references to "excessively high voltage" in older manuals relating to the "black wire"

3) Hook up an ohmmeter, (U,-.,LU onms1, one prooe

attached to the black wire and one probe to the regulator base. It must read zero ohms resistance.

Several ohms resistance indicates a frayed or broken black wire.

NOTE: Voltage output will be excessively high if this black wire is broken anywhere between the

regulator and the stator.

OR.....it could just be a junk new regulator

 

[GLJ]

Yep, I only had half the question - GLJ has the complete question: overcharging can be low voltage on the brown (from drop at the switch (etc) per Gary) but also can be a bad ground to the regulator. It's not well discussed in newer manuals, but here's two references to "excessively high voltage" in older manuals relating to the "black wire"
View attachment 239104
3) Hook up an ohmmeter, (U,-.,LU onms1, one prooe

attached to the black wire and one probe to the regulator base. It must read zero ohms resistance.

Several ohms resistance indicates a frayed or broken black wire.

NOTE: Voltage output will be excessively high if this black wire is broken anywhere between the

regulator and the stator.

OR.....it could just be a junk new regulator

Using a ohm meter is a ok test, problem is it's a static test. My Ohm meters (Fluke) only have 9 vol batterys so they don't really push much current through.
A better test is dynamic. See what the voltage is when the circuit is under load.

 

[75XSFLORIDA]

Yep, I only had half the question - GLJ has the complete question: overcharging can be low voltage on the brown (from drop at the switch (etc) per Gary) but also can be a bad ground to the regulator. It's not well discussed in newer manuals, but here's two references to "excessively high voltage" in older manuals relating to the "black wire"
View attachment 239104


3) Hook up an ohmmeter, (U,-.,LU onms1, one prooe

attached to the black wire and one probe to the regulator base. It must read zero ohms resistance.

Several ohms resistance indicates a frayed or broken black wire.

NOTE: Voltage output will be excessively high if this black wire is broken anywhere between the

regulator and the stator.

OR.....it could just be a junk new regulator

“attached to the black wire and one probe to the regulator base. It must read zero ohms resistance.”

TO THE BLACK WIRE AND BASE AT THE REGULATOR SIDE OF THIS ALL-IN ONE UNIT? Or are you saying do this test on the old mechanical regulator??

 

[jpdevol]

Nope. Just clarifying that one of the possibilities to the overcharging is faulty wiring and one half the potential causes of the faulty wiring is the ground part of the circuit. So, testing the continuity of the harness black that connects to the new regulator - checking for 100% continuity to battery negative. Also the voltage that the regulator is seeing on the brown wire.

Or a faulty regulator unit.

 

[75XSFLORIDA]

“attached to the black wire and one probe to the regulator base. It must read zero ohms resistance.”

TO THE BLACK WIRE AND BASE AT THE REGULATOR SIDE OF THIS ALL-IN ONE UNIT? Or are you saying do this test on the old mechanical regulator??

Right but you said attach one probe to the REGULATOR BASE….new one, or all in one unit is what im asking?

 

[GLJ]

“attached to the black wire and one probe to the regulator base. It must read zero ohms resistance.”

TO THE BLACK WIRE AND BASE AT THE REGULATOR SIDE OF THIS ALL-IN ONE UNIT? Or are you saying do this test on the old mechanical regulator??

Since you have the all-in one currently on the bike I think it's safe to assume that's is the one means. He also said to check at the black wire and brown wires going to the all-in-one reg.

 

[jpdevol]

Those were just passages from the manuals I was using to clarify - and resulted in confusing.

Just do the tests Gary and GLJ have suggested above - they explained it better

 

[magoo66]

Gary, main switch is OEM NOS probably a year old. I had it apart two weeks ago when I first had the problem just to look internally and it’s flawless inside. Bright shiny bear aluminum and you can eat out of it. That’s what startling me about this bike, everything is flawless.

Just curious.Are these NOS OEM switches like you’ve shared,easy to find and change?Just curious if the old original was causing problems or you changed for cosmetic reasons.

 

[75XSFLORIDA]

Just curious.Are these NOS OEM switches like you’ve shared,easy to find and change?Just curious if the old original was causing problems or you changed for cosmetic reasons.

Extremely easy and yes just for cosmetics!

 

[magoo66]

Extremely easy and yes just for cosmetics!

No further questions on the switch.Thank-you

 

[75XSFLORIDA]

Those were just passages from the manuals I was using to clarify - and resulted in confusing.

Just do the tests Gary and GLJ have suggested above - they explained it better

Does anyone know what this ground wire is for? Connects under tripletree and other side in tip of tripletree, under guage cluster??

 

[jpdevol]

That should be the ground for the handlebars and connect to the stud for the bar clamps under the top clamp - see if it's the correct diameter

 

[75XSFLORIDA]

That should be the ground for the handlebars and connect to the stud for the bar clamps under the top clamp - see if it's the correct diameter

Yes that exactly where its at…. It was a tad corroded, so I hit it with some 1200 sandpaper. That would cause my crazy voltage issue would it?? I also took the ignition switch cover off underneath of the cluster just to look at all the solder points and everything looks good. I did not take the ignition switch apart though.