Updated: 2013 XC300, Help Turning The Lights Back On
 

Help!

I started undoing electrical tape on my XC to fix a broken wire on my e-start, and have opened Pandora?s Box! FYI, E-start is all good... now to fix the lights!

What voltage should be coming into the light switch on the yellow wire? Is it DC or AC? I see one leg of the yellow comes from inside the stator / gen cover. The other yellow conductor that feeds the yellow leg of the light switch (3-way splice) comes from the regulator. I?m reading .1VDC or 1VAC while checking the yellow with the bike running and revving.

I get 12VDC at the brake light. The starter relay seems good, the two fuses are good and the bike will kick start without a battery (key on tho). It also sends charge voltage to the battery leads too (no batt connected for that test).

Help! What voltage should I see on yellow, and where to look next?!?

Thanks!

Things to keep in mind: The stator puts out only AC voltage, you can't measure DC there. White to ground is full output, yellow to ground is slightly less output.

Your lighting operates on AC voltage (yellow wire). The rectifier/regulator clips the AC voltage to keep your bulbs from burning out. It also provides some DC power for battery charging (sourced from the white wire). You need the engine running to create AC voltage, it should measure about 15VAC.

You can check resistance values for the stator (wires disconnected) to see if it is funtional.

My notes are based on the 2011 wiring, yours might be slightly different. Follow the colors in your specific wiring diagram. You need the exact diagram for your bike. Estart bikes are wired differently than non-estart bikes.

Thanks Neil! I figured it would be AC, but why do my brakes give me 12vdc???That chart is exactly what I needed, and my conductors are the same color as yours. It looks like the charge coil is the main issue. I read:

105.6 between red and green
15.5 between red/white and black/white (close to tolerance)
Open between yellow and ground, and
.5 between yellow and white (starts around 1 and drops to .5)

This combined with the lack of AC at my light switch leads me to believe I get to replace some goodies inside the left case. Any idea what needs to be ordered? Looking at GasGaspartsguy it looks like the ?ignition comp.? is one unit and over $300! I?ve never replaced a stator but am handy with a meter and a wrench.

Thinking about this overnight I have to ask... Do i want to replace the stator with another GasGas unit? Does anyone know if this is a common failure for these? At only 5 years old, having a stator issue reminds me of early 90s sportbikes...

The only saving grace is it looks like the previous owner pounded the snot out of this bike doing Hard Enduro. What do you all think? Worth replacing or will it just fail again soon? I haven?t ridden at night yet but I like the idea of keeping the bike in original shape with all features working.

Open between yellow and ground is a problem. It could be a broken wire/bad connection. What do you get from white to ground? If that is OK and you get battery charging, then you should pull the flywheel and check all the connections.

The lighting windings are grounded. Yellow is at a point at about 85-90% of the total windings, white is 100% of the windings. The reduced output (yellow wire) just makes it easier for a voltage regulator to clip at say 13VAC.

The white wire gives full output so the rectified DC has enough energy to actually charge the battery, say 15VDC. As a test you could connect the white wire to where the yellow wire goes to your lighting and then get some headlight function with the engine idling.

This would indicate that you have a connection problem somewhere regarding the yellow wire. It could be corrosion on the stator connections. If the bike has been hammered hard, the chances are good that water has entered the ignition side of the motor.

I see very few complaints about GG stators. They seem to be very reliable. The AC voltage regulators on the other hand are not so good. Many people with non-estart (AC only) bikes have burned out bulbs. The estart bikes seem to be fine since they use a combined regulator/rectifier unit.

As to your tail light, it could be operating on DC voltage. I don't have a 2013 wiring diagram to check.

Thank you again Neil. You have been a huge help!

Between white and ground I also read open. I tried swapping yellow for white and no lights, no voltage... If it matters, I read a short between white and yellow. I assume that?s ok since they are connected to the same coil on the diagram.

I also double checked the battery charge voltage and read 6VDC or 10VAC. At this point I can?t tell you what is DC or AC in here because I am working with a meter that reads both (lost my good one). Whatever the brakes are, they are fed by the red conductor on the keyswitch, and appear to draw power from the red/black on the starter relay.

I opened the ignition cover but I don?t have a flywheel puller. I think you are correct because I removed the little module attaching to red and green and the screws had rust on them. Months ago when i replaced my starter bendix and ignition sproket the gasket was hosed, I?m sure plenty of water got in before I bought it.

Thanks again, I wish the electrical diagram in the manual included all the little bits of info you?ve provided! Either way I will search for a new stator. If it got wet I?m betting it?s only a matter of time before I lose the real important coil and get to enjoy a long walk theough the woods back to my truck!

With yellow to ground open and white to ground open, it's a good bet that the stator has failed. The stator is just one continuous winding that goes around multiple posts. The direction of winding changes as you go from one post to the next. As you say, if you lose the single winding that powers the CDI, you will be walking.

Based on your comment it looks like DC power is used for the tail light. And yes you will get continuity between white and yellow. Think of it like a transformer. The yellow is just tapped off at a different point in the winding. That is what the wiring diagram is indicating. They show it at about 50% just for sake of clarity on the diagram.

Note that the stator windings could still be OK if you have a broken solder joint where it hooks up. You could also lose the ground due to severe corrosion but that is not likely unless the stator screws/stator plate/motor mounting bolts/frame tabs are in really bad shape. Get yourself a flywheel puller and remove the flywheel. It's the only way to see what is happening with the stator..

Too funny, I ordered a flywheel puller earlier today. I?m interested to see what it looks like inside there before throwing any money at it.

Update:
 

I opened the flywheel this morning and it looks pretty good in there. No opens or shorts on the wire harness, but I did find what looks like a broken conductor between coils (pic attached). Some of the coils are covered in black goo too...

The flywheel is stamped Japan so I am off to my local friendly YamaKawi dealer to see if my stator isn?t off something they carry?!?... We already have reason to believe the clutch on my 2013 is the same as an 2007 YZ450f...

Well, I struck out at Yamaha, but thankfully a local KTM dealer (MPC), not only had stators in stock, but was willing to help me look! Those guys were very cool to work with and I gues sold GasGas years ago.

We found a stator off a 2014 KTM 300 XCW (I believe, don?t know all their models names lol) that appears to be identical down to the conductor color, size and windings. They even let me check it with my meter to be sure we were looking at the same thing. The funny part is it didn?t give me the exact numbers Neil posted above for yellow and white, but even with my rinkydink meter I could tell I was metering a coil, and we were close. I will have to attach it to my plate and splice my wiring harness since this has the KTM connectors. I prefer to solder, but there is minimal space to work with and I solder better with a legit bench setup (which I don?t have).

I think I?m gonna take a good look at this puzzle before I decide where to cut and splice. I am thinking under the tank if I can, so i don?t have to pull the flywheel if I have an issue. Stay tuned and I?ll follow up after I check voltage. Hopefully my regulator is still good!

Edited to add pic of measurements from new KTM stator.