2017 EX high beam wiring question

[TXBikerGuy]

It appears that the high-beam + lead for the 2017 LED headlight module has power whether or not the high beam switch is activated. It has been suggested to me that Honda may be using a ground wire to switch the power to the high beam. Apparently this is common on the FJR's with LED headlights.

Thanks to Paris and his 2018 post about installing a headlight modulator, I have the wiring diagram for the 2017 LED headlight and it shows a green wire as the ground (-) for the high beam.

Has anyone had the need to figure out if the 2017 EX model does in fact use the ground switching method and if so, is that #1 green ground wire the right one to use?

For context, I'm wiring up my Clearwater Darla lights and the manual controller knob is set up to connect to the high beam power lead so the lights to to full brightness whenever you switch on the high beams. When I wire the lights per their instructions, the knob doesn't work at all because of the power flowing to the high beam lead full-time.

[max]

Yup, switched to ground.
If you look at the headlight diagram there is a blue/white wire labelled " dimmer" which connects to the high/low beam and "passing switch" on the handlebars .
It appears the actual switches are capable of handling 5 ampere loads but since it looks that they control an electronic driver care should be used to not damage the controller( inside the electronic headlight ) with let say a relay induction voltage spike present when the switch opens like an ignition coil principle.

EDIT

Looking at their website it appears the on/off switching is done with a relay, what needs to be done is change the wiring at the relay so the coil is supplied from the red battery wire instead of the black ones.

To be safe there needs to be a 2 amp diode ( 1N4007 ) in anti-parallel with the coil so that the diode does not conduct when the 12 volts is applied but suppresses any reverse voltage spike in excess of 0,7 volts.
in other words the ring marking on the diode connects to the positive 12 v ( red ) supply wire and the other lead connects to the switched coil wire which is connected to the blue/white wire from the headlight.

[TXBikerGuy]

Yup, switched to ground.
If you look at the headlight diagram there is a blue/white wire labelled " dimmer" which connects to the high/low beam and "passing switch" on the handlebars .
It appears the actual switches are capable of handling 5 ampere loads but since it looks that they control an electronic driver care should be used to not damage the controller( inside the electronic headlight ) with let say a relay induction voltage spike present when the switch opens like an ignition coil principle.

EDIT

Looking at their website it appears the on/off switching is done with a relay, what needs to be done is change the wiring at the relay so the coil is supplied from the red battery wire instead of the black ones.

To be safe there needs to be a 2 amp diode ( 1N4007 ) in anti-parallel with the coil so that the diode does not conduct when the 12 volts is applied but suppresses any reverse voltage spike in excess of 0,7 volts.
in other words the ring marking on the diode connects to the positive 12 v ( red ) supply wire and the other lead connects to the switched coil wire which is connected to the blue/white wire from the headlight.

Thanks for the confirmation on the switched to ground deal. I found out how to program the Darla's so that I can get to 100% brightness without having them tied to the high-beam so I think I'm just going to go with that. Don't want to risk messing something else up by tapping the trigger wire into it.

[pekingduck]

I agree with Max.

There's no schematic to the internals of the stock LED headlight controller, and that headlight retails for more than $1000, so use caution. It looks to me like the black/red wire is the high beam power wire, hot all the time, and the circuit is activated by grounding the blue/white through the high/low switch.





If you're unsure of the wiring, another way around it is to use a common automotive relay used for auxiliary horns and lights. It's a good idea anyway since the Darlas draw 4 amps, and it would have it's own fused circuit, and not be taxing the LED circuit. This is the way I'd go, so it would be activated by either high beam or passing button.

[TXBikerGuy]

I agree with Max.

There's no schematic to the internals of the stock LED headlight controller, and that headlight retails for more than $1000, so use caution. It looks to me like the black/red wire is the high beam power wire, hot all the time, and the circuit is activated by grounding the blue/white through the high/low switch.





If you're unsure of the wiring, another way around it is to use a common automotive relay used for auxiliary horns and lights. It's a good idea anyway since the Darlas draw 4 amps, and it would have it's own fused circuit, and not be taxing the LED circuit. This is the way I'd go, so it would be activated by either high beam or passing button.

Thanks, PD. The Darla's actually come with a relay that plays a role in the control knob and probably make it safe to tap into the blue/white wire. But, for all the reasons you and Max have highlighted--capped off with the nearly $1000 cost of a new headlight, I am just skipping the high-beam trigger wire altogether. I've reprogrammed the controller so I can get 100% brightness without the wiring risk (thanks to tech support at Clearwater for that tip).

I ride with my brights on 100% of the time during daylight hours anyway, so just dialing up the controller to the MAX setting accomplishes what I want. I only turn down the Darla's at night if there is steady oncoming traffic. My goal is to throw as much possible light toward people who have the ability to harm me by turning left!



Appreciate the quick and helpful replies. Love this forum.

[the Ferret]

Well that's a lot of light. Should do the trick