Headlight relay harness for Honda NT650 Hawk GT
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If you've ridden a Hawk at night you've probably noticed that the headlight leaves something to be desired.
I've got two solutions to this problem. One is a suplementary headlight wiring harness that uses heavy gauge wire and automotive relays. It is described on this page.
The much more effective (and more expensive) is a complete headlight swap from a Honda CB600F/Hornet/599. Click here for details on this.
Answers to questions
If you want to replace the whole reflector and lens, consider my Honda 599/hornet 600 kit, which I believe is the best stock-looking light you can have on the Hawk for (almost) any price.
The wiring is deficient for several reasons,
In the case of the Hawk the power has to go from the battery, through the main fuse, through the ignition switch, through the main fuse box, through the right hand side starter switch (the headlight turns off when you press the starter) across to the left side high/low beam switch, and then finally to the headlight. All of the wiring is pretty small gauge, (18 I think) and each of the switches adds resistance.
When I did my measurements I measured 9.6 volts across the headlight with the headlight on, but not the engine, as compared to 12.8 volts at the battery. When I hooked the bulb directly to the battery using big wire the voltage was 11.9 volts.
That 2.3 volts makes a significant difference in the amount of light put out by the bulb, as the relationship between power and brightness is not linear, a properly powered 100 watt bulb puts out noticably more light than two 50 watt bulbs.
Some people will just use a high wattage bulb in the stock harness to get some more light. This works, sort of, but it's not a good idea. Here's why:
What this harness supplies is some marine grade large gauge wire from the battery directly to the headlight, switched by two Bosch automotive relays that are controlled by the stock wiring harness. The relays draw very little current so heat and arcing in the switches isn't a problem.
The harness includes a male H4 plug so there's no cutting into the stock harness, if you want to remove it, the bike is still stock.
The kit includes everything you need to install the harness except for some common tools.
Click for a very large picture.
There aren't a lot of options.
The standard ones are:
For $10 extra (and some measurements) I'll make it work with your fairing. I'll need some information about the fairing before I can build the harness first:
What's listed here is for the 88-91 Hawk GT only. If you can give me lots of measurements, I'll entertain setups for other bikes, but you'll be expected to do a lot of the measurements and the research. If we do something, you will take full responsibility for the fit, and any potential benifit. I'll gladly help you, but I can't guarantee how well it will fit, or if it will help.
If you want to know if it could help, measure the voltage across the headlight when it's on, if there's a significant drop compared to the voltage at the battery, then the wiring is wimpy and could be helped.
If you can find a place for the relays to mount gracefully, and a way to get a bunch of wires from there to the battery and headlight, then there's potential.
|no-name Korean made 80/100
watt bulb (80 watt low)
|(ea) Out of stock, sorry.
|no-name Korean made 55/100
watt bulb (55 watt low)
|dual light setup
|removable diode for low beam
use with high beam
|depending on location
|paypal charge for harness
|Honda 599 kit
|Click here to see details on this.
|599 kit shipping
|depending on location
|paypal charge for 599 kit
Unfortunately Paypal charges me money to accept payments. My margin on these is small so I've got to make it up. Sorry about that. However, you can pay with a credit card through paypal, or send me a check or money order.
Shipping is $8 - $15 for the lower 48 states, depending on where you are, if it's to a business or home, etc. For AK, HI, Canada, or other countries, send me mail and I'll find out what it costs. I'll entertain faster/other shipping options, and even rush "Build me a custom one now!" orders, but since I don't necessarily have a finished harness waiting around to be shipped, anything faster than ground might be a waste of money.
For weird setups (project bikes, funny fairings, stuff like that) Send me mail and we'll talk about it.
and tell me what you want. I accept paypal or money orders or even personal check if I have some idea of who you are or if you're willing to let it clear before I ship.
Nope, it's pretty easy.
No knowledge of electricity or mechanics or physics is required.
If you can read and you aren't color blind, you can do this.
Paper instructions are included, and an HTML version is available here: www.mahonkin.com/headlight-harness/instructions.
Typically I hear that it takes about 1/2 hour.
Technically, if the bulb is running brighter, more power is going through it, which means the alternator has to generate more power to keep up with the draw.
The power draw is increased if you use a dual light setup, or high-wattage bulbs.
However, it's not really a concern unless you've got two 100/80 watt bulbs running both high and low beams, and you've got an electric vest, and electric socks, and gloves, and pants, and ......
I'm exaggerating, but really you don't have to worry about it. The alternator is rated at 240 watts at 5,000 RPM, and the bike (without headlight, but with gauge and running lights) draws about 60 Watts. If you include 110 watts of dual 60/55 watt low beam, it's still only 170, leaving a resonable margin.