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Ahhhhh, so maybe I didn't need to do the mod in the first place. This LED light was "supposed" to be plug and play. Comes with an inline driver that is supposed to stop error messages due to lower wattage.

Does anyone know if the OPT7 LED bulb needs either of these mods?

Thanks!
David
 

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Ahhhhh, so maybe I didn't need to do the mod in the first place. This LED light was "supposed" to be plug and play. Comes with an inline driver that is supposed to stop error messages due to lower wattage.

Does anyone know if the OPT7 LED bulb needs either of these mods?

Thanks!
David
http://www.vn750.com/forum/19-electrical/87625-guide-bypassing-reserve-lighting-unit-2.html

Thorn wrote this guide too.

edit : I guess this is the same one he posted earlier.

Looks like the RLU just isn't happy with the OPT7.

I would keep the blue wire mod. You have an LED headlight now, and the relays in the JB are trouble. You just bypassed one.
 

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Hey that is a good idea if a stator goes out, pull the headlight fuse and just ride in the daytime. You can do the switch mod later if you decide to replace the stator. I would guess pulling the fuse would cut the power to everything related to the head light circuit. Will have to look at a good wiring diagram, the ones I've found so far for the vulcan are terrible, small, black and white, plus blurred out.
Pretty sure its the LAW to run a headlight on your Motorcycle here in sunny Florida.So......my Stator pooped out so tried the "Battery tender" thing,was OK but really tough to figure when that battery would die...then leave you sitting/walking.Not a enjoyable way to ride!! :frown2:
 

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Did this, made going through the lights electric system much better. Plus I like it just coming on with the key and knowing the headlight is working right away.

Sent from my XT1585 using Tapatalk
 

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Got the RLU bypass done a few days back. It solved the flicker-y Headlight light on the dash! And, after the blue wire mod, the light comes on when the key turns, which is very nice. Also, the LED has a much better spread and is just brighter at night.

I also replaced my rear brake/running light with two LEDs. Changing these and the headlight to LED has really reduced the dim of lights at idle while the brake light is being activated like at a stop light.

There is a barely noticeable flicker with the new LEDs only at idle, but it's very minimal and I don't think I'm going to worry about it.

Thanks for the help guys!
 

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For the Blue wire mod cons - Headlight stays on when key is turned on, which obviously takes power away from starting.

What I did was splice in a good quality mini toggle switch between the ground headlight wire inside the headlight cover, drilled a small hole in the lower head light cover to run the mini toggle switch through. The switch can then be off for starting, then easily turned on when warmed up and ready to ride. Very inexpensive easy fix to get full power for starting, after doing the Mod.
Can you explain this with wire colors and step by step instructions I did the blue wire mod and would like to install a switch?

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The ground wires on this bike are black w/yellow stripe. Ground switching is the best way to go when it's possible, no chance of it shorting out. My voltmeter is switched on the ground side.

If you get the AGM battery, the headlight staying on should be no problem.
 

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Hi Guys (and Gals) 👋 I’m in England and have just joined. I’ve recently replaced my stator and rectifier and suddenly have the dreaded “Headlight not working” scenario. I think a mod was done to the bike before I got it (late last year) as the headlight used to come on with the ignition switch. I can’t see the “blue wire mod” at the fuse box end though and the connector where one would expect the power to come onward from the fuse is empty, so where does it go and is it really protecting the headlight circuit????☹
My question is - is the headlight relay replaceable? And if so how? As this seems to me to be the obvious solution...
I’m no electrician, so please excuse me if the answer is staring me in the face!
Safe journeys all
Ade
 

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Hi Ade,

After the standard blue wire mod, the headlight fuse will be unused, and the taillight fuse will provide power to the headlight.
Replacing the headlight relay requires desoldering the old component and soldering a new one back onto the circuit board. It is not a horrible procedure if you're comfortable soldering, if you can find the right component to buy.

Regarding the rest of your problems, I suggest starting a new thread specific to resolving the problems on your bike since it sounds like there's going to be a lot of investigation involved and we should try to keep the post count low on this "how-to" thread to keep things clear for future readers of the blue wire mod.
 

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What is the “reserve” lighting unit for?
And how do I check it’s working please?
As still baffled as to why I have power going to the blue wire from the headlight fuse, but no power at the light... 🤔
Cheers
 

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What is the “reserve” lighting unit for?
And how do I check it’s working please?
As still baffled as to why I have power going to the blue wire from the headlight fuse, but no power at the light... 🤔
Cheers
The reserve lighting unit will automatically switch from low beam to high beam if it detects a filament failure. Without you having to toggle the headlight switch. If there is any intention on going to an LED headlight, it could cause flickering because the LED bulbs do not consume as much power as the stock incandescent bulbs. It can be bypassed very simply by using a jumper across 2 pins on the connector. That mod can be easily found on here (with pics) by running a search on “RLU bypass”
 

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It actually moves it to a pin that is protected by the TAIL fuse, also 10 amps, so the headlight is still completely protected. You can even move the 'dash' lights (red/blue wire) to the originally empty spot (pin 17, tail-light fuse protected), and move the headlight (blue) to where the red/blue wire was. That gives you all the benefits of the mod while keeping the headlight on the headlight fuse for OCD people.

Crowley said the pros and cons would surely be discussed, but nobody discussed! Here's my take on it:

Pros:
1. Protects against a dead headlight due to headlight relay failure.
2. Your headlight comes on as soon as you turn the ignition to 'on'.
3. No wires cut means this mod is completely reversible.

Cons:
1. Since the headlight will come on when you turn the ignition to 'on', it lowers the available voltage to the starter motor.


I'm also going to recommend an additional step to the mod:
Remove the smaller, ten pin molex connector from the junction box. Using a small screwdriver, release the retaining pin on the yellow wire's blade connector (pin 9), which should be the second wire up on the back row.​
Cover the blade connector in shrink wrap and heat it until securely insulated.​
Use a small zip tie to gently but firmly secure this wire to the bundle of yellow stator wires that go to the rectifier/regulator so it doesn't wander somewhere it shouldn't.​


Additional pros:
4. Protects your stator from burning out if the headlight relay coil shorts out. (the safer the better)
5. Protects the starter relay (the one outside the junction box) from the constant unregulated voltage pulses it usually gets from the stator.
There's another con to it you won't be able to jump the bike if need be cause it causes the voltage to back fire and starts heating the jumper cables I did and it didn't work so I just decided to order a new wire harness
 

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There's another con to it you won't be able to jump the bike if need be cause it causes the voltage to back fire and starts heating the jumper cables I did and it didn't work so I just decided to order a new wire harness
I've jumped my bike with the blue mod in place, no problem. Voltage back fire? Sounds like you might have a short in your system.
 
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