150cc JMStar won't charge battery By helix803 (Read 435 times)

[helix803]

My charging system isn't working.

The scooter runs fine, lights work - I am getting 13v DC at the connector.

It is an 8 coil stator with a five wire r/r. I don't know what stator to buy if that is the problem. AC or DC?

It has a total new wiring harness from Partsforscooters. I bought a new r/r because the original didn't match the harness. It was a four wire.

Here are some test results. Are they off? What to test next?


WHITE TO YELLOW: 0.00


WHITE TO GREEN: 00.8


YELLOW TO GREEN: 00.6


GREEN TO FRAME: 00.0

[FACE PLANT FOR LIFE]

Now I don't claim to be an expert in electricals by any means, but I'm pretty sure you have to test each of those wires independantly with the black probe GROUNDED (on the frame, maybe) or you will never get any readings (I'm assuming you're testing for voltage). Does the voltage to your battery fluctuate with revs? Rev it up and tell us what you get AT the battery terminals. The R/R could be bad. Some R/R's can have very little charging with brights headlights, and vice versa. I've had R/R's not give off enough charging voltage to register at the battery terminals with bright headlights, and also R/R's where there is barely any headlight voltage but HUGE (over the top) charging power.


Edit: You're testing ohms. Check the voltage, please!

[helix803]

Yup, checking continuity per manual and as referenced by another thread of a similar problem. Will check voltage again tomorrow. I checked the voltage at the battery earlier. I was getting around 8 volts at 5,000 rpm. I know the charging system isn't charging or my battery wouldn't keep dying and I'd have ~12 volts at the battery. My question is what part in the charging system has failed.

[Bashan]

By testing ohms you essentially did continuity tests on the yellow to white and ground. The yellow center taps to the white so you should have continuity which you do at zero impedance. Both white and yellow ground to case and stator frame so zero, or close, which you have...that's normal. Check your white wire set at AC with one probe in the end of the wire and the other probe to ground, should be around 25v AC with bike started...it varies but close to 25. Probe polarity does not matter, it is AC, it is not directional flow. Reattach to R/R and then pull the yellow off the R/R and do the same test....should be 15ish. If those stator values are OK the 8v DC at the battery is a giant red flag, it is then your R/R. Checking at the battery IS directional since it is DC but if you put the probes to the battery backwards it simply reads negative DC voltage and the value is still valid. Rich

[helix803]

Apr 27, 2014 0:43:30 GMT -6 Bashan said:

By testing ohms you essentially did continuity tests on the yellow to white and ground. The yellow center taps to the white so you should have continuity which you do at zero impedance. Both white and yellow ground to case and stator frame so zero, or close, which you have...that's normal. Check your white wire set at AC with one probe in the end of the wire and the other probe to ground, should be around 25v AC with bike started...it varies but close to 25. Probe polarity does not matter, it is AC, it is not directional flow. Reattach to R/R and then pull the yellow off the R/R and do the same test....should be 15ish. If those stator values are OK the 8v DC at the battery is a giant red flag, it is then your R/R. Checking at the battery IS directional since it is DC but if you put the probes to the battery backwards it simply reads negative DC voltage and the value is still valid. Rich

Hey! It was the R/R. I wired in a spare 4-pin for the 5-pin, and now the charging system is charging fine. 12.45V.

[helix803]

Dangit! Scooter was charging yesterday, but not today.

Fire sale: JMStar 150 on Craig's List in Charlotte

[Bashan]

Are you still using the four pin R/R as opposed to the OEM five. I wasn't real comfortable with that. Rich

[helix803]

Well OEM was four, I switched to five when installed the new harness. Am going to order a new five pin R/R right now.

-Michael

[Bashan]

I think that roasted it. I'd recheck my stator voltages too again. They're pretty hard to roast but it can be done. I know this because...um ..er...Alley did it! Yeah, it wasn't me...it was Alley!

[helix803]

I think i mighta fried the new regulator. That area smelled funny and the harness is warm. I did not find any short to ground. At idle it still puts out 6v and at 5,000 rpm 8v. I am ready to throw in the towel.

[helix803]

Hallelujah! Installed new stator and have a whopping 15V