To use the factory wiring to power aux LED lights, do I need

to add a fuse and a relay to the factory fuse box (behind the cover in the trunk)?
There are 2 locations to plug relays and fuses into in that fuse box. The upper left (I think it was the left; it was a couple days ago I looked) is where the relay and fuse are plugged in for the factory heated grips. There are spaces adjacent to them for another relay and fuse, but on my fuse box the pictogram indicates they're unused. Since American-market NCXs don't have the auxiliary light option, I was thinking to myself that perhaps they just mark them that way for those of us here, but that if I plug a relay and fuse in then I'll have all the wiring done for some LED lights.

Am I dreaming here? Thanks for any help you can offer.

I may be off on my understanding of that fuse box and your idea, but here goes... If you put a relay and fuse in there, how are you going to find the wiring that it applies to?

I just added LED driving lights and a Powerlet power outlet among other things. I added a new in-line fuse wired direct to the battery for the lights, and another for the outlet. The wiring harness on the NC is a tight tangle to mess with as far as I'm concerned, and you have to remove lots of bodywork to find your way around.

I always assumed the non-USA driving light option plugged into the standard optional Honda accessory harness, because one of the four connectors in that harness also includes the high beam signal. I don't know what the second relay socket feeds, if it feeds anything. Only one optional relay is shown on the schematic diagram.

If you already have the Honda relay and harness, you can connect your lights there. There are places for four options on that harness, assuming the total draw doesn't exceed 7.5 amps.

I do have the Honda harness (and Honda heated grips and aux power outlet). I read that the high-beam 'signal' was there, but that wording wasn't quite what I expected, so I decided I didn't know whether or not the existing relay system was set up to supply both the high beam and aux lights simultaneously or not. The total current draw of the new LEDs (PIAA) will be ~18 watts apiece, including both the bulbs and control circuitry.

Perhaps I'll just order the connectors for the factory harness from ...wherever it is that a courteous fellow on here posted about... and plug 'em in and see.

MZ5 said:

I do have the Honda harness (and Honda heated grips and aux power outlet). I read that the high-beam 'signal' was there, but that wording wasn't quite what I expected, so I decided I didn't know whether or not the existing relay system was set up to supply both the high beam and aux lights simultaneously or not. The total current draw of the new LEDs (PIAA) will be ~18 watts apiece, including both the bulbs and control circuitry.

Perhaps I'll just order the connectors for the factory harness from ...wherever it is that a courteous fellow on here posted about... and plug 'em in and see.

Click to expand...

I'm not sure how the optional Honda LED driving lights work, but on my aux light setup I used a Skene Designs light controller. It has the capability of using a 12 volt input to switch the lights from some dimmer programmed setting to full brightness. So on mine, the lights run at 50% brightness on low beam, then when I switch to high beam the 12 volt high beam signal from the connector commands the LEDs to go to full bright.

My understanding, limited as we don't have the Honda driving lights here, they plug into the acc harness. That plug on the harness has high beam trigger, keyed power, ground. That other relay spot in the fuse box may not have power. Not unusual for a fuse box to have an extra relay or fuse spot that isn't powered or sometimes they have power but nothing on the other side. If you want to be industrious you can get to the back of the box and with the right terminals use it for an OEM style add-on circuit.

My bike had driving lights when I bought it. The dealer installed them. They are not the Honda LED's though. They are a PIAA light so not sure if this will align with your conversation but at the time my bike did not have the Honda Accessory Harness. They wired them in some other way. I have never looked it over that well to see what they did.

I think mine may be like Hollow Road Riders. I have only been in the battery compartment once when I installed my 12V port. I did see an in-line fuse with some excess wire so I'm pretty sure my lights are connected direct to the battery. I manually turn them off and on with a button switch although they are kept on at all times.

I'm using the subharness for every accessory on my NC. The option 6P connector provides switched power, backup power, and left/right signals.

I had to rewire the backup power pin (red/white) to the subharness (blue) because it was unconnected. (I suppose it's connected normally when the alarm harness is connected before the subharness, but I can't be 100% sure because I haven't found any alarm wiring diagram or the OEM alarm harness so far...)

ste7ios said:

I'm using the subharness for every accessory on my NC. The option 6P connector provides switched power, backup power, and left/right signals.

Click to expand...

I used the 6-Pin Connector for the power connection of the relay with a 5 Amp Fuse on my Relay Harness that I made using a mating connector from a double end 12" Cable Assembly (CON-60 Cable Assy) that I got from All Electronics (www.allelectronics.com) here in the SVF. The LED Pods are powered through this connector via the relay. I also picked up a couple of the 3-Pin Cable Assemblies (CON-30 Cable Assy) too. I used one of these cable assemblies and the last 3-Pin Connector on the Honda Sub-harness as the "Enable" for the Auxiliary Light Switch Assembly used to power the coil of the relay.

I do believe that the wire colors from the Honda Sub-harness that I used are were used were "Brown" and "Dark Green" on both connectors.

The Vision X LED Pods (10 W) that I bought only draw about .75-.85 Amps per unit, 1.5-1.7 Amps for both units. Their operation voltage is 9-48 VDC. Their brightness between the the engine being "OFF or ON" does not seem to change.

The color coding is as the following:

Red/White (R/W) - Backup Power
Violet/Red (V/R) - Switched Power
Light Blue (Lb) - Right Turn
Orange (O) - Left Turn
Green (G) - GND


The subharness has different coding:

Brown (Br) - Switched Power
Blue (Bu) - Backup Power (Unconnected)
Green (G) - GND