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Discussion Starter #1
Hello fellow riders, I was gifted a 1994 Vulcan 750 from a friend recently with a few issues . I’ve resolved all of the issues save one, the headlight flickers then winks out.

When warming up the bike the head light comes on like it should, when I reduce the choke while the bike drops down to a normal idle the light will flicker and then go out. I’ve found by flicking the flasher button the light will come back on, and stay on until the RPM drops back down at a stoplight. I have noticed it happens only at certain RPMs, so I 'm thinking it might be in the GENERATOR area? This is a cat and mouse game for most of my 11 mile ride to work (and ride home).

This was the final straw for giving me the bike he said, hey I’m good with that!

I asked him what he has done to try and solve the problem; he said he replaced the voltage regulator. The problem did not go away after he did though. Then he got a bonus from his work and got a bigger newer bike and did not want to chase the problem anymore. One of the issues was replacing the battery with a new one......so it's not a battery issue.

Thanks for any input you might have, can’t wait to solve the issue and get to worry free ridding.
 

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..have a vulcan good day!
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Hello fellow riders, I was gifted a 1994 Vulcan 750 from a friend recently with a few issues . I’ve resolved all of the issues save one, the headlight flickers then winks out.

When warming up the bike the head light comes on like it should, when I reduce the choke while the bike drops down to a normal idle the light will flicker and then go out. I’ve found by flicking the flasher button the light will come back on, and stay on until the RPM drops back down at a stoplight. I have noticed it happens only at certain RPMs, so I 'm thinking it might be in the GENERATOR area? This is a cat and mouse game for most of my 11 mile ride to work (and ride home).

This was the final straw for giving me the bike he said, hey I’m good with that!

I asked him what he has done to try and solve the problem; he said he replaced the voltage regulator. The problem did not go away after he did though. Then he got a bonus from his work and got a bigger newer bike and did not want to chase the problem anymore. One of the issues was replacing the battery with a new one......so it's not a battery issue.

Thanks for any input you might have, can’t wait to solve the issue and get to worry free ridding.
My first thought is the Junction Box (JB)...there are small Relay's soldered on the board, is one of them a Headlight Relay ?
....thinking the relay (contacts) might be stuttering.
 

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The Vulcan is designed do the headlight only comes on after the engine starts (or at least fires) I believe the switch for that is in the junction box. It could also be a loose connection almost anywhere. If you absolutely can't find it, wire the light to a fused wire from the battery, and put in another switch. I had to do that on my Goldwing, the stock switch completely fell apart.
 

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My guess is corroded connection, crappy bulb, or the JB

kenny
 

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check your ac voltage from the stator on the yellow lead that goes to the headlight relay, or just check all the stator ac signal voltages at the regulator. if it was a contact or ground issue it would work the opposite when the load is higher one would think.
 

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Sparky!!!
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I thirdly say its a junction box issue. The head Light Relay is not locking up propperly, but I would check to make sure that you are getting voltage to pin 9 of the JB (like said before it should be ac voltage.
 

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I am also thinking Junction Box, but I would first open and inspect the lefts side controls.

If playing with the flasher button temporarily fixes the light, then the relay must already be engaged....or so logic would suggest.

Open up the control housing and clean/inspect the contacts and look for pinched or damaged wires.

If you still think it is a Junction box issue, you can PM me as I have a spare. We can swap Junction boxes and for a small fee and shipping I can just fix yours and keep it as my spare.
 

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Discussion Starter #8
I am also thinking Junction Box, but I would first open and inspect the lefts side controls.

If playing with the flasher button temporarily fixes the light, then the relay must already be engaged....or so logic would suggest.

Open up the control housing and clean/inspect the contacts and look for pinched or damaged wires.

If you still think it is a Junction box issue, you can PM me as I have a spare. We can swap Junction boxes and for a small fee and shipping I can just fix yours and keep it as my spare.


I'll not be getting back to it untell the weekend, I'm sure I'll do all of the above! Thanks for the inputs!
 

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Discussion Starter #9
No such luck on a simple fix, chased all the conections, removed the head light and used a tester with the same results. Replaced the ground wire from the battery (it looked iffy) still finding It does it when the motor "pops" down in RPMs.

think it will have to go to an expert, money I don't want to spend.
 

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No such luck on a simple fix, chased all the conections, removed the head light and used a tester with the same results. Replaced the ground wire from the battery (it looked iffy) still finding It does it when the motor "pops" down in RPMs.

think it will have to go to an expert, money I don't want to spend.
when the light flickers on and off....do you hear a clicking noise from the fuse box (junction box)?
 

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You did try a different bulb, right?
 

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What about trying the headlight relay bypass, moving the blue wire to the empty hole?
 

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R/R = Relocated Redneck
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Discussion Starter #16
So an update on the light issue….

One day while ridding home from work the RPMs dropped to near null at a stop light, from then on I had to keep it revved up around 4k to keep it from stalling out and getting it home. The next morning I pulled the battery and set it to charge…. It was full charged. OK failed plug?.. Pulled all the plugs, dirty but in good shape. I moved them to different locations and re started the bike. The bike started right up idled fine road it to work the next day with no idle issue. On the way home I had a short period of rough idle on the way but it went away.

The next morning I turned the key and noticed the headlight came on before the bike started (having issues with the idle I did not pay attention to the headlight). So currently the head light works fine, except for the fact it comes on with the key, not waiting for the bike to be started.
 

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So currently the head light works fine, except for the fact it comes on with the key, not waiting for the bike to be started.
You need to determine if the headligt relay bypass was done. Where is the blue wire plugged in on the junction Box??

If the blue wire was already moved to bypass the relay, then the headlight will come on with the ignition and not wait to get a signal from the stator output. In this scenario, it must be a loose connection causing the headlight to flicker.

If the bypass was NOT performed, you need to ensure you are getting good AC signals out of the 3 stator wires. If the stator checks out, then it must be that the relay in the Junction Box is defective.

As I said before, I have a spare JB. PM me and we will work out the trade for your bad one.

As far as the stalling/low idle issue goes, I think it might be unrelated to electrical. More likely dirty carbs and jets for the idle circuit....try a heavy dose of seafoam and get it to idle so it works the gunk out of the passages. Maybe even backblow the carbs.
 
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