High Beam Signal Wire

Lewis

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So, the blue high beam +12 volt signal wire in the 3-wire sub-harness connector doesn't send a signal since the bike's headlights switched over to LEDs form incandescent. Anyone know how to make auxiliary lights turn on when high beam is turned on?
FWIW - 2020 NC750X DCT with ADVMonster model 60 lights with dimmer and high beam bypass (hence the need for the high beam signal).
 

CapeMan

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Hmm, yeah, I did this about a year ago so I'm replying based my (flawed) memory. I started from scratch, so didn't already have a high beam bypass and dimmer, and I'll just pass on what I did. Not sure how it might work with the stuff you've already got.

As I recall, there's a switched 12V+, a ground, and a blue signal wire on that connector in the aux wiring harness (and, BTW, you'll need to also have installed the relay and fuse into the Honda fuse panel that activates the aux wiring harness for this to work), The signal wire reads about 5V+ when the low beam is on and 0V when the high is on.

EDIT: This applies to model years after 2017, the ones with the LED headlights. If you've got an older version, with halogen headlights, this blue signal wire appears to have 12V+ when the high beam is on.

To switch aux lights on only when high beams are on, you'll need power them via a relay that's normally closed and passes the 12v+ power to the lights but opens (disconnects) when it sees 5V+ from the signal wire, i.e. low beam is on..

It's also possible to rig the aux lights to switch from low to high output with the low/high beam on your head light. To make this work:
First wire the 12V+ to the aux lights thru a Pulse Width Modulator or PWM. (A PWM is smallish, relatively inexpensive electrical device that is commonly used to adjust the light output from an LED). Connect the power from the PWM to your aux lights and adjust the PWM to reduce their output to a much lower level that's comfortable for oncoming drivers.​
To get full aux light brightness along with the headlight high beam, wire a normally closed relay in parallel with the PWM and have the relay open when it's sensing circuit sees 5V+ from the blue signal wire. With this wiring configuration, you'll have full 12V+ to the aux lights when the high beam is on (signal wire = 0V & relay closed) because the PWM is being bypassed by the relay. Then when you switch to low beam (signal wire = 5V+), the relay opens and forces the all the power to the aux lights to go thru the PWM, which you previously adjusted to reduced light output.​
Voila!​

I seem to recall that I spent maybe $40 for a solid-state relay and PWM. If I get a chance sometime in the next few days, I'll see if I can dredge up a record of the specific parts I used and post them here.
 
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Lewis

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Thanks for the quick response CapeMan. My aux lights are able to do double duty (lower output level and full power) through the PWM dimmer with high beam bypass (see http://stores.advmonster.com/rotary-led-dimmer-with-high-beam-bypass/).
Does that help/change anything in your thinking?
Hmm, yeah, I did this about a year ago so I'm replying based my (flawed) memory. I started from scratch, so didn't already have a high beam bypass and dimmer, and I'll just pass on what I did. Not sure how it might work with the stuff you've already got.

As I recall, there's a switched 12V+, a ground, and a blue signal wire on that connector in the aux wiring harness (and, BTW, you'll need to also have installed the relay and fuse into the Honda fuse panel that activates the aux wiring harness for this to work), The signal wire reads about 5V+ when the low beam is on and 0V when the high is on.

To switch aux lights on only when high beams are on, you'll need power them via a relay that's normally closed and passes the 12v+ power to the lights but opens (disconnects) when it sees 5V+ from the signal wire, i.e. low beam is on..

It's also possible to rig the aux lights to switch from low to high output with the low/high beam on your head light. To make this work:
First wire the 12V+ to the aux lights thru a Pulse Width Modulator or PWM. (A PWM is smallish, relatively inexpensive electrical device that is commonly used to adjust the light output from an LED). Connect the power from the PWM to your aux lights and adjust the PWM to reduce their output to a much lower level that's comfortable for oncoming drivers.​
To get full aux light brightness along with the headlight high beam, wire a normally closed relay in parallel with the PWM and have the relay open when it's sensing circuit sees 5V+ from the blue signal wire. With this wiring configuration, you'll have full 12V+ to the aux lights when the high beam is on (signal wire = 0V & relay closed) because the PWM is being bypassed by the relay. Then when you switch to low beam (signal wire = 5V+), the relay opens and forces the all the power to the aux lights to go thru the PWM, which you previously adjusted to reduced light output.​
Voila!​

I seem to recall that I spent maybe $40 for a solid-state relay and PWM. If I get a chance sometime in the next few days, I'll see if I can dredge up a record of the specific parts I used and post them here.

Thanks for the quick response CapeMan. My aux lights are able to do double duty (lower output level and full power) through the PWM dimmer with high beam bypass (see http://stores.advmonster.com/rotary-led-dimmer-with-high-beam-bypass/).
Does that help/change anything in your thinking?
 

CapeMan

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Thanks for the quick response CapeMan. My aux lights are able to do double duty (lower output level and full power) through the PWM dimmer with high beam bypass (see http://stores.advmonster.com/rotary-led-dimmer-with-high-beam-bypass/).
Does that help/change anything in your thinking?



Thanks for the quick response CapeMan. My aux lights are able to do double duty (lower output level and full power) through the PWM dimmer with high beam bypass (see http://stores.advmonster.com/rotary-led-dimmer-with-high-beam-bypass/).
Does that help/change anything in your thinking?
Okay, it looks like you've already got the functional equivalent of my individual PWM and relay combo and all you need is a 12V+ signal that's only powered when High Beam is on. What you've got is a 5V+ signal that's only powered when the Low Beam is on ... so all you really need to do is reverse that signal and bump the power to 12V+

It's relay time. Start with this relay: http://timers.shop/Multi-Functional-3V-18V-Time-Delay-Relay-Timer-5-amp_p_12.html. This is a solid-state and weather-proof relay that's highly programmable by the user so it's easy to get it to NOT pass on 12V+ when the signal is "Hi" (5V+ will do), then pass on 12V+ when the 5V+ signal stops; just what you need.

On a side note, these relays are hugely useful for a whole variety of applications us motorcycle types might want. I've suggested to them that they add a user-programmable PWM function that triggers from Hi or Lo signals with Full output in the reverse. It'd be a one-shot solution to our aux lighting problems and they responded that they'll be adding this functionality, well .... sometime. They also sell a brake light strobe for really lo $ too.
 

Lewis

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Okay, it looks like you've already got the functional equivalent of my individual PWM and relay combo and all you need is a 12V+ signal that's only powered when High Beam is on. What you've got is a 5V+ signal that's only powered when the Low Beam is on ... so all you really need to do is reverse that signal and bump the power to 12V+

It's relay time. Start with this relay: http://timers.shop/Multi-Functional-3V-18V-Time-Delay-Relay-Timer-5-amp_p_12.html. This is a solid-state and weather-proof relay that's highly programmable by the user so it's easy to get it to NOT pass on 12V+ when the signal is "Hi" (5V+ will do), then pass on 12V+ when the 5V+ signal stops; just what you need.

On a side note, these relays are hugely useful for a whole variety of applications us motorcycle types might want. I've suggested to them that they add a user-programmable PWM function that triggers from Hi or Lo signals with Full output in the reverse. It'd be a one-shot solution to our aux lighting problems and they responded that they'll be adding this functionality, well .... sometime. They also sell a brake light strobe for really lo $ too.
Ok, it took me some time to understand all of this (thanks to help from my son) but I think I've got it now. I ordered the relay and button board from that website you suggested and will hopefully get things working as intended.
Thanks again CapeMan.
 

Lewis

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I got the programmable solid state timer relay (didn't need the timer function) and a bunch of 3 pin and 4 pin plugs for the sub-harness and everything works great - dimmer controlled brightness to the aux lights (always on with switched power) and full power (7000 lumens) with the high beam switch. This is all made possible due to the programmable relay being able to send +12 volts to the aux lights when it senses 0 volts (down from +5 volts) on the bike's sub-harness's blue so-called high beam trigger wire.
The programming took some time to figure out (credit goes out to my son for that), but does work.
PS The vendor confirmed that the solid state relay is water-resistant, not waterproof.
 
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