I've decided to install a new headlight on my bike. The current setup is two bulbs, one is on for low beam and both on for high beam, with two wires going out of each (h11?). Here is a short video of someone taking apart theirs (I have the same setup): https://www.youtube.com/watch?feature=player_detailpage&v=sseygM8ipQA#t=41

The new headlight will have one 55w HID bulb, with 3 wires going to it (h4?).

My thinking is this:

  • Connect two male h11 (?) To the existing connectors (to avoid splicing).

  • Take the positive wires from each bulb connector and wire from the front to under the saddle (may be unnecessary wiring, but might be easier than finding the other end?).

  • Each positive wire goes into it's own relay.

  • Each relay is connected to the battery (and fuse)

  • Each relay has one wire going to the new headlight, I.e. from under the saddle to the front.

  • One relay is for low beam and other for high beam

  • Connect 3rd wire from new headlight to battery negative pole.

This is the first time I do such wiring, and I was wondering if someone could offer some advice, e.g. (+anything else useful):

  • Is the above correct, and am I missing anything?
  • What kind of relays do I need?
  • What gauge of wire to relays from existing connectors?
  • What gauge of wire from relays to new headlight?
  • Anyone know a diagram for wiring this?

Any help is much appreciated, thank you.

I looked in the manual, and the fuse for headlight/brake light is 20amps (bike is victory highball 2012). Does that answer the question? I don't know much about these things, but if I get the right wiring and parts, I should be able to follow instructions.

The HID kits I've seen come with ballasts, but I thought I would be safer with relays (?).


  • What is the difference in power draw between the existing headlamp(s) and the HID? You mention the HID is 55w, but nothing on the original lamps. The reason I ask is, if the draw is no more than what the HID is (or if HID is less), whatever wiring is in place right now will be effective enough for the HID. IOW, if it could handle the draw of the regular headlight, it will work for the HID. Your guess on the wiring seems to be accurate. It is how I'd look at doing the wiring for the conversion. Oct 16, 2014 at 11:28
  • I don't think you can go wrong with relays, though don't know if you would truly need them. Just ensure you hook them up correctly and you'll be golden. Relays are cheap insurance. Also ensure the wiring you use is of sufficient gauge to supply the power you need. Oct 17, 2014 at 20:46
  • I was under the impression, that the standard Halogen was 55 watts and the HID was 35 Watts, so the Ballast was needed to protect the wiring and HID light, and to providing high voltage to ignite the xenon gas.
    – Frank
    Feb 12, 2016 at 14:45

1 Answer 1


absolutely DO NOT replace a BALLAST with a RELAY.

They perform different functions completely and are in no way related.

Relay = Switch

Ballast = Current Regulation

A solid state relay may have some voltage limitation attributes but you need to be sure that it matches the ballast that will be provided with your HID kit. I HIGHLY recommend you use those. If you want to switch the circuit with a relay, great, do it...the point is that the two devices (relay and ballast) are mutually exclusive.

http://en.wikipedia.org/wiki/Electrical_ballast http://en.wikipedia.org/wiki/Relay

The last line of your question made me concerned. "The HID kits I've seen come with ballasts, but I thought I would be safer with relays (?)."

Regarding grounding. Do your best to tie into your common ground rather than going straight to your battery. If you want to use 'earth' ground on the bike, that would be better than making the commoner mistake of a bunch of bad wiring to the battery which I've seen to many times in my life. Every time someone grounds an aftermarket electrical device to their battery 5 kittens die. Don't be a kitten killer.

Sorry for the dramatic bold and using the answer as a way of sending the message but I wanted to be absolutely sure you saw this. If I've misunderstood, apologies in advance.

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