Topic: K3 750 voltage problem

[MauiK3]

Yesterday I began my search for my voltage gremlin. It began a few months ago and I am just now having time to spend with it.
 It happens is when I turn on the ignition switch the dash lights come on but very dim. When I check voltage almost anywhere it is less than 6. With the battery disconnected it's 12.6.
This is a new thing, the bike has been running fine up until now.
I am starting by disconnecting things like the alternator, I will be checking grounds as well.
I'm thinking something is bleeding off voltage but not quite a short, no fuses have blown.
I'll need to trace down every circuit, disconnecting, until I find the culprit.
Good social distancing project.

[69cb750]

If battery reads 12.6 volts and instrument lights reads 6 volts typical cause is bad ground or oxidized wire that feeds fuse block.

[MauiK3]

Does this make a bit of sense?
I went through the harness disconnecting things one at a time. Long story short, everything in the headlight can was disconnected, horn, brake light switches, coils, points wires, tail lights, turn signals, instrument clusters, etc. Problem still persisted. I unhooked the alternator connector, oil pressure switch, neutral switch.
I removed and checked the two ground connectors, the large one on the left side of the engine and the smaller one up by the seat latch. All good there.
Then I unhooked the starter solenoid and removed it, problem went away, I could turn the key switch on and still have over 12 volts.
I don't see anything in the diagram that would explain this other than an internally shorted solenoid.

[rotortiller]

With the starter not engaged the solenoid should draw nothing. Just remember the solenoid shares connections with other items. If it were me I'd disconnect the 2 small bullet connectors and the starter lead then check it out. Likely the draw is not the relay and elsewhere, normal or not. You may just have a 5hitty battery that cannot handle any kind of load.

[MauiK3]

Im thinking this is something to do with the starter motor. If I touch the starter + cable to the battery nothing happens. Slight spark. I guess the starter comes out for a look.

[MauiK3]

Starter out, pretty dead, doesn’t do anything when I “bench test” it to the battery.
I’ve always felt unsure about this motor, it’s the original (I think).
This starter has the lead hard wired into the windings, no connection lug on the outside, I’ve seen other starters where the wire is separate and connects to a lug on the starter and the other end goes to the solenoid. Does anyone know why there appear to be two types?
I’m thinking that since my wire to the starter is not the best where it enters the motor case I’ll need to replace the starter.

[rotortiller]

Like I suggested, it may well be your battery.

[ekpent]

 Did you test that starter off a known good car battery or the bikes ?

[PeWe]

Good battery is vital.
My charging indicator LED alarmed for overvoltage last year on my K6. It did not help to reduce max voltage on regulator.

I understood thst battery was really bad at this years first start when battery died after one start.
Next did not turn the crank. I was happy rhat I was home, not far away.
 Battery has been charged a few days every 2nd month or more during winter and before too .

Changed battery and needed to crank up the voltage by 1 turn clockwise on regulator.
Now OK.

It is easier to supervise the voltage level when riding with help of a voltmeter. It is connected to black and green inside headlight bucket.

Here a little low with old battery, light and ignition on, engine not running.

This will show that it take time to get back to full voltage after city riding. Highway speed will charge.

[MauiK3]

Now it's time for me to feel stupid.
My battery reads 12.4 volts, even after not being on the tender overnight and it does not bump the starter or even make a spark.
I took the starter out to the Jeep and it ran fine, man that little motor has some torque!!
So my problem has been a battery all along, I just suckered myself with my voltmeter. It's a new meter and it's a Fluke so I put too much faith in the reading without considering the battery may be bad and have good voltage but essentially no amperage to offer.
I have the worst luck with batteries, I don't know how many times I've had one die the day after the warranty was up. This battery is a Scorpion AGM, I guess I won't get any more Scorpions, it's 13 months old.
Now I need to find a quality battery that can be shipped to Maui.
Ugh

[Deltarider]

Why not have the standard Yuasa lead acid battery?
No modifications needed.
No risk of error connecting terminals, ruining the rectifier.
Exactly the right dimensions, so no 'surprises'.
Can live up to 6-7 years.
Can handle spikes in voltage no prob.
Original look. (Just too bad Yuasa abandoned the original 100% clear case)
Cheap.
Against: occasionally you have to add some distilled water.
If Yuasa has a maintenance free battery on offer, that is exactly the right dimensions and layout, I'll have that one in the future. Have not seen it yet.

[Stev-o]

I've had good luck with Scorpions, usually last 3 yrs or more.

Look into MotoBat if you want to switch, I run them in my Kawasaki since Scorpion doesnt make one for them.

https://www.amazon.com/MotoBatt-Battery-CB1000C-CB1100F-Motorcycles/dp/B01B6HFBMW

[MauiK3]

I'm pretty much stuck with not many choices, most vendors won't ship a battery here, have to go to the Harley dealer or Napa Auto.

[Stev-o]

I'm pretty much stuck with not many choices, most vendors won't ship a battery here, have to go to the Harley dealer or Napa Auto.

So there is a downside to living in Paradise?!

Let me know if I can help.

[JimM68]

The Autocraft AGM battery I bought 8 years ago is still going strong.
And unlike a yuasu lead acid, it doesn't self discharge just sitting.

Bike could sit a year, and will still crank and run.

Highly recommended

Sent from my moto z3 using Tapatalk

[HondaMan]

Yuasa. Maintenace-free. Needs a slightly longer battery strap, though, as it is 0.25" taller than the regular lead-acid version.

[ekpent]

Maybe somebody from the mainland could secretly ship one of your choosing over there to Paradise.

[Stev-o]

Yuasa. Maintenace-free.

Thx HM, didnt know they made that version.

MauiMan - Does Amazon deliver to Paradise?!

https://www.amazon.com/Yuasa-YUAM62H4L-YTX14AHL-BS-Battery/dp/B0018F3MP6