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Blue wire bypass - headlight relay mod

32577 Views 57 Replies 24 Participants Last post by  Mikeee15
This guide bypasses the headlight relay, lighting your headlight when you turn the key, instead of when the engine turns.

Don't ask me about the pros/cons of this; I'm sure it will be discussed.

Video detailing the procedure at https://www.youtube.com/watch?v=C1_1MTfiJb8

On the left side of the bike remove the side cover. Unscrew the bottom screw and pull the side cover off. If you are sitting on the side of the bike, facing the side cover, pull directly toward you.

http://i16.photobucket.com/albums/b5/crowley1027/vn/IMG_20140323_061053.jpg
You will see a Palm sized black box with two connectors coming out the right side of the box. One is a smaller ten pin, one is an 8 pin.

http://i16.photobucket.com/albums/b5/crowley1027/vn/IMG_20140323_061153.jpg

Don't make the mistake I made - don't touch the ten pin connector. I pulled the blue wire from the 10 pin and moved it to the 8 pin. This is WRONG.

Pull out the 8 pin connector.

http://i16.photobucket.com/albums/b5/crowley1027/vn/IMG_20140323_061246.jpg

There is a blue wire. Pull the blue wire out of its spot (or push it from the front of the connector to reduce stress on the wires) and move it to the empty spot on the same connector.

http://i16.photobucket.com/albums/b5/crowley1027/vn/IMG_20140323_061333.jpg
http://i16.photobucket.com/albums/b5/crowley1027/vn/IMG_20140323_061559.jpg

If the spade connector pushes out as you push the connector in, just connect the plug, then push the spade connector into the empty spot to secure it.

Operation complete.
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Wouldn't it be easier to get new jumper cables in order to adequately charge the bike's battery and not be faced with voltage surges? I use EPAuto cables on my car, I believe that similar ones will work for a motorcycle too.
Please stop commenting on technical threads. There are plenty of us here that can help that know how to work on these bikes. If you're here to "learn" just follow along. This is getting annoying fast and if you keep it up I'll suggest you get booted again. I'm asking nicely this time.
I looked over his posts and decided to kick him off the forum. He apparently doesn’t even have a motorcycle and in some replies sounded like a robot or a foreigner that was using a translator app.
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This “person’s” phrasing was a dead giveaway to the phoniness. Once used the term “mechanical wrench”, who says that?
The other point I made against them was if you’re looking to get a motorcycle and/or learn about them why would you join this forum? Why pick a forum dedicated to a single bike type that hasn’t been produced for 15yrs.
He called the knife I posted “unkillable” wtf does that mean? LOL 😂
This is pretty old subject but I did this at one time. Can't really remember why, but probably the headlight wasn't coming on after starting. Anyway, I also put a toggle switch in line and mounted it on the side cover. That way I am in control of headlight on/off at all times - just like the bikes in the old days. Some times I ride without the headlight just to save the stator some work.
The stator and R/R are balanced for the load output of a stock bike, keeping your headlight off doesn’t really help the stator, it’s still going to produce as much power. If anything, cutting down power usage gives your R/R more juice to convert to heat to dissipate.
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So those who convert to LED lights harm the R/R?
So those who convert to LED lights harm the R/R?
I’ve converted all my lights to LED, I don’t know I’d say it’s “harming” the r/r. Although electrically speaking its creating more load for it. If I do the math I freed up about 70w by switching out all the stock bulbs. I added driving lights and a phone charger and I still have some to burn if I want to add something else without worrying about taxing the bike.
Oh, I see. Kinda like an inline toggle switch frees up wattage then.
Yes it’ll free up wattage to use elsewhere but has no real bearing on the stator, so to stick with the original point the r/r is more critical in this scenario.
I suppose, ideally, you should use the most power you can while still maintaining a good charging voltage. That's where a dash mount voltmeter can help.

Saw a nice Widder brand heated vest going cheap in the auction yesterday.
Some of what I'm going to say is speculation, so take it with a grain of salt.

The original R/R is a shunt style, which takes any extra pixies being generated and sends them back to the stator by dropping the resistance between the legs of the stator, short-circuit style. This leads to the wires themselves being the highest resistance items in the circuit, and overheats them (like melting a cheap extension cord while using a high amperage tool). This can bake the R/R if the bike's systems arent using a high enough percentage of the energy produced by the stator. If you dramatically decrease the energy used by the bike's systems (via LED conversions) you increase the amount of short-circuiting being done by the R/R. I THINK that in this setup the stator is always producing it's maximum current.

A Mosfet R/R increases the resistance of the circuit, blocking the amount of current that can flow between the legs of the stator, and just sips off what it needs to run the bike's systems. This would lead to cooler wiring, since the overall current between the stator and the R/R is lower. I THINK this also decreases the drag on the engine. I remember seeing a demonstration once where a kid would turn a crank generator, and the demonstrator would flip a light switch to make the generator light up a bulb. The crank instantly got harder to crank because it was now actually doing work, whereas before with an open switch, there was no current, so the generator wasn't technically doing any work. Same should apply here, where the overall work is lower because no current is being shunted. Any decrease in wattage on the bike would translate to lower heat in the wiring, and less gas wasted. There's probably a diminishing return R/R heat reduction buildup as wattage demand decreases, since the mosfet must be providing resistance based on load.

If anyone can back up or refute my speculations, I'd love to hear it.
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Some of what I'm going to say is speculation, so take it with a grain of salt.

The original R/R is a shunt style, which takes any extra pixies being generated and sends them back to the stator by dropping the resistance between the legs of the stator, short-circuit style. This leads to the wires themselves being the highest resistance items in the circuit, and overheats them (like melting a cheap extension cord while using a high amperage tool). This can bake the R/R if the bike's systems arent using a high enough percentage of the energy produced by the stator. If you dramatically decrease the energy used by the bike's systems (via LED conversions) you increase the amount of short-circuiting being done by the R/R. I THINK that in this setup the stator is always producing it's maximum current.

A Mosfet R/R increases the resistance of the circuit, blocking the amount of current that can flow between the legs of the stator, and just sips off what it needs to run the bike's systems. This would lead to cooler wiring, since the overall current between the stator and the R/R is lower. I THINK this also decreases the drag on the engine. I remember seeing a demonstration once where a kid would turn a crank generator, and the demonstrator would flip a light switch to make the generator light up a bulb. The crank instantly got harder to crank because it was now actually doing work, whereas before with an open switch, there was no current, so the generator wasn't technically doing any work. Same should apply here, where the overall work is lower because no current is being shunted. Any decrease in wattage on the bike would translate to lower heat in the wiring, and less gas wasted. There's probably a diminishing return R/R heat reduction buildup as wattage demand decreases, since the mosfet must be providing resistance based on load.

If anyone can back up or refute my speculations, I'd love to hear it.
I have also read the stator runs at full output all the time, relative to rpm of course.

Side note, just the fact that there are magnets spinning around the copper will produce heat. If you search Lenz effect at YouTube you should see some cool videos. Magnet vs. copper is somewhat anti-gravity too btw.
I love the scientific/engineering aspect that this topic brings up, if Kawasaki just made the stator easier to access no one would put this much thought into it lol. I haven’t broken out the electrical engineering books but these threads bring back good memories.
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I have also read the stator runs at full output all the time, relative to rpm of course.

Side note, just the fact that there are magnets spinning around the copper will produce heat. If you search Lenz effect at YouTube you should see some cool videos. Magnet vs. copper is somewhat anti-gravity too btw.
Yeah, I do know that there are "stationary" eddy currents even if there is no actual current flow, per se. The laminated nature of the windings on transformers (and motor winding armatures might be laminated for the same reason?) are to help reduce those eddys, keep things efficient, and reduce the related heat. That is about as far as I've dareed go down into the physics hole that goes deep, deep to the core of the existence of reality.
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Eddy currents! That's what I couldn't remember earlier. Those laminations should wick heat away.

So many dead stators have oil coking and ash built up on them, but the rest of the engines are relatively clean. Makes me think there's some extra heat in the stator itself.

There's a thread where the poster engineered an oil line spraying onto the stator to improve cooling. Don't recall if it improved anything, think maybe kawi has relied on oil splash to cover the stator. You get oiled if you start it without the oil cap.

In one Lenz effect video, magnets spinning at 14,000 on a router table, a 2" copper pipe glows orange when held over the magnets.

A magnet dropped through copper pipe can't drop at free fall, the eddy current slows it down.
This guide bypasses the headlight relay, lighting your headlight when you turn the key, instead of when the engine turns.

Don't ask me about the pros/cons of this; I'm sure it will be discussed.

Video detailing the procedure at

On the left side of the bike remove the side cover. Unscrew the bottom screw and pull the side cover off. If you are sitting on the side of the bike, facing the side cover, pull directly toward you.

http://i16.photobucket.com/albums/b5/crowley1027/vn/IMG_20140323_061053.jpg
You will see a Palm sized black box with two connectors coming out the right side of the box. One is a smaller ten pin, one is an 8 pin.

http://i16.photobucket.com/albums/b5/crowley1027/vn/IMG_20140323_061153.jpg

Don't make the mistake I made - don't touch the ten pin connector. I pulled the blue wire from the 10 pin and moved it to the 8 pin. This is WRONG.

Pull out the 8 pin connector.

http://i16.photobucket.com/albums/b5/crowley1027/vn/IMG_20140323_061246.jpg

There is a blue wire. Pull the blue wire out of its spot (or push it from the front of the connector to reduce stress on the wires) and move it to the empty spot on the same connector.

http://i16.photobucket.com/albums/b5/crowley1027/vn/IMG_20140323_061333.jpg
http://i16.photobucket.com/albums/b5/crowley1027/vn/IMG_20140323_061559.jpg

If the spade connector pushes out as you push the connector in, just connect the plug, then push the spade connector into the empty spot to secure it.

Operation complete.
so I’m another victim of the headlight not working and did as you said, which worked. However, when the headlightswitch is in low beam the bulb actually starts to let of smoke. But high beam doesn’t. Any ideas why. Maybe I should as another inline fuse the headlight but that would be redundant and not make sense since it’s running thru a fuse from the junction box.
This guide bypasses the headlight relay, lighting your headlight when you turn the key, instead of when the engine turns.

Don't ask me about the pros/cons of this; I'm sure it will be discussed.

Video detailing the procedure at

On the left side of the bike remove the side cover. Unscrew the bottom screw and pull the side cover off. If you are sitting on the side of the bike, facing the side cover, pull directly toward you.

http://i16.photobucket.com/albums/b5/crowley1027/vn/IMG_20140323_061053.jpg
You will see a Palm sized black box with two connectors coming out the right side of the box. One is a smaller ten pin, one is an 8 pin.

http://i16.photobucket.com/albums/b5/crowley1027/vn/IMG_20140323_061153.jpg

Don't make the mistake I made - don't touch the ten pin connector. I pulled the blue wire from the 10 pin and moved it to the 8 pin. This is WRONG.

Pull out the 8 pin connector.

http://i16.photobucket.com/albums/b5/crowley1027/vn/IMG_20140323_061246.jpg

There is a blue wire. Pull the blue wire out of its spot (or push it from the front of the connector to reduce stress on the wires) and move it to the empty spot on the same connector.

http://i16.photobucket.com/albums/b5/crowley1027/vn/IMG_20140323_061333.jpg
http://i16.photobucket.com/albums/b5/crowley1027/vn/IMG_20140323_061559.jpg

If the spade connector pushes out as you push the connector in, just connect the plug, then push the spade connector into the empty spot to secure it.

Operation complete.
It took a little Coaxing to get the wire out of the connector. BUT it slipped right in the empty slot. Voilla Headlights!!!! Thank you!! Easiest explanation Ive ever seen. 2 thumbs up!!
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