Low voltage at stock lighting wires

[2k3kdx220r]

I've got my hands on a US model 2001 KDX200 at the moment and am trying to get the stock headlight and tail light working - both are dark. Bike runs perfect.

Light switch is unhooked.

On the yellow wire from the stator I get 40VAC at idle and 90+ VAC with a blip of throttle. With the meter grounded to the frame or ground wire makes no difference.

At the head or tail light wires I get about 3VAC whether grounding my meter to the frame or to the other wire.

When I hit the kill switch the voltage goes up to about 6VAC at the wires for an instant just as the engine dies.

Bad voltage regulator? Any way to test it with my meter?

 

[2k3kdx220r]

Welp, I just bought a 2003 KDX 200 voltage regulator from Flea Bay for $19 shipped. Will definately let you all know what happens.

Another wrinkle to my description above is that the red wire that goes to the headlight is loose and may very well have shorted against the grounded spring loaded bulb base. The black ground wire is still intact on the housing. I get 0 resistance continuity from the ground wires to the triples or cylinder head bolts so it shouldn't be a ground issue.

I figure that getting 40-90 VAC on the yellow wire from the magneto - and If I pull the VR I get that at the wires to either the F or R lights - both with and without the switch, then adding the VR gets me 3 VAC at the wires, grounded to the other wire or the frame, it's just gotta be the VR is toasty. Will find out soon enough I guess! Beats paying $115 for a new OEM to find out at least!

 

[BSWIFT]

Your discription leads me to say the voltage regulator is bad. Nice troubleshooting BTW.

 

[John Harris]

If you want it to last more than one ride, put an led bulb in the tail. Available from all auto parts stores. John

 

[2k3kdx220r]

BSWIFT - I hope so, but I'm used to seeing the voltages come out too high when a VR goes bad on a DC street bike. Maybe this is different will have to wait and see what my 03 KDX200 VR coming in the mail does. Seller was up front and said that the bike was a non running basket case when he bought it to part out, so I may not get a good part - never know.

Does anyone with a service manual see a procedure for testing a VR? I get no continuity and no resistance between the two leads, would think you'd get some resistance, but since it's AC based maybe my meter can't do ohms on AC, don't know.

John Harris - I had a new 2003 KDX 200 that I rode for a season and a half, but about 2000 miles on it, 90% trail and 10% road. I never blew either bulb but the whole tailight housing seemed very loose on this 01 200. I may very well get an LED too for the power savings so the headlight gets more juice. It's an 1157 or 1156 taillight right, which one?

Thanks for chiming in guys.

 

[2k3kdx220r]

I stopped in the local Kwak dealership today and got my hands on a factory KDX H-model service manual for a minute.

Voltage regulator test in the kohm range, should show 15~16k ohms with positve lead on Black/Yel and 15~60k ohms with positive lead on the Brown (negative lead of meter on the other color in each case).

I get infinity / open circuit - no reading at all on either combo.

If anyone has a loose VR or would be kind enough to unplug their VR and throw a meter on it, I'd be interested to see what you get, so when I test mine when it lands at work mid-day, I'll know if I've got a good part.

At any rate I've helped some future searcher!

Search terms:
KDX 200 220 KDX200 KDX220 lights lighting light head headlight tail taillight doesn't don't not work works working voltage volt volts AC DC VAC VDC regulator test low high

:nener:

 

[BSWIFT]

Most regulators will just open up giving you no voltage out, however, before they open up completely you will see a drastic drop in voltage due to the higher resistance. By your use of terminology specific, you already knew that.