EC 250 2008 no power from light coil

[mrfreezer]

Hi guys, I have just bought GG EC 250 2008 Racing.. I has not lights mounted. Today I tried to mount front light, but I found out I have no power in yellow wire from ignition. I have measured on yellow wire in harness to CDI. The yellow wire is short to ground. How can I measure it to be sure what is faulty?? I have just found out that I need to measure AC not DC... Will measure it tommorow.. Is it possible that voltage regulator is faulty and voltage after regulator is too low?

[Neil E.]

Don't worry about the CDI wires if the engine runs fine.

Find the stator wires coming out of the engine and unplug them. Connect an AC voltmeter from yellow to ground and see what reading you get when the engine is running. Also test white to ground, it should read only slightly higher.

This will show if the stator is making power. If you get good readings then we can investigate further.

[mrfreezer]

I have just measured the yellow wire from stator to ground and the reading was 28V... I did not measure white one and it is still unplugged.. Is there connector for white wire from stator too??

I have measured yellow wire when unplugged with 28V coming from coil, but when I plugged it in and tried to measure yellow wire on regulator to ground no voltage.. The base of the regulator has to be grounded??

[Neil E.]

There is normally a connector for the white wire, but we are only concerned with the yellow wire at this point. If you are getting 28VAC, then the lighting coil is working. The only question is how much current it can provide. This is not important at the moment.

I believe the regulator is a one wire device, so yes the regulator base must be grounded. If you have no voltage at the regulator input wire, it is most likely that you have a bad connection somewhere.

It's time to cut the harness open to trace all the yellow wires. Follow the yellow wire that connects to your stator yellow wire. You should be able to measure your 28VAC as you move away from the stator (bike running).

The regulator is supposed to clip excess voltage (anything over 14VAC). The only way you'd get nothing is if the regulator itself is short circuited to ground internally or there is no power getting to it. Now we are back to bad or open connections somewhere.

If the regulator wire is disconnected, do you get 28VAC coming in on the mating wire?

[mrfreezer]

My regulator has 2 wires.. one yellow (input) and black (ground).. but its metal base is touching the frame, so it is grounded too... will try to unplug the yellow wire from regulator and measure it there... If I unplug the regulator I should measure 28VAC on headlight socket too??

[Neil E.]

You are right about the regulator. It is the black wire that must be grounded. Once you unhook the regulator yellow wire, all other yellow wires should have the same voltage as you are seeing at the stator. Keep in mind that the respective switches must be on to measure voltage at the headlight socket unless your low beam is directly connected to a yellow wire.

[mrfreezer]

So I have measured 36 VAC on yellow wire from stator but no voltage on regulator... so I started to look for damaged wire and I found out unplugged connector under the tank... So I plugged it in, and everything worked for one day... than I found out, I have yellow wire shortened to ground... So again looking for damaged wire.. I found out that rear brake switch wire was damaged in the clamp under the tank.. repaired it and now everything works fine... thanks a lot guys... now just wondering what flasher relay to use...