HoebSTer said:
I know everything is included in the kit, but what about the mechanics of it? On the VSTrom site, people were adding an Eastern Beaver Relay kit to the OEM Headlights. Why? Does this reduce the voltage loaded onto the switch when we turn from low to high beams or something?
Hoebster,
To elaborate a bit on what Venture explained, think of your houses 120V wiring for a light. If you have a dining room fixture with 5 60watt lights (total of 300watts), the wiring in your wall runs from your breaker box through a wall switch then to the light (unless the switch is past the light in the circuit, but I'm trying to keep this simple). All of the wiring and the switch all have to be of sufficient gauge and capacity to handle the entire load since it all flows directly through the wire and switch. When the switch is off, the circuit is broken so no "juice" gets to the light. Flip it on and the circuit is completed so the fixture lights up.
You can wire your bike the same way, but you would have to have wiring of a thick enough gauge and a switch that can handle the entire load that the lights will draw. In this case, the LED draw next to nothing, so that isn't the best example, but HID ballast or some other higher draw accessory would mean you need larger gauge wire for everything. With a relay, the full power load only has to travel from the power source (directly from the battery or from a fuse block), then through the relay, then directly to the accessory. The relay takes the place of the switch that breaks the circuit. Now the wiring going to and from the relay and your actual switch need only be of a gauge that will handle a very small amount of juice. When you flip your switch on, the little bit of juice tells the relay to close the circuit so the power flows to your lights. This can be seen in all manner of switches. From stereo amps to factory auto lights, there are large gauge wires that supply the power and small gauge wires between the switch and relay. No reason to run all that power through many feet of cable and a high capacity switch, all of which is more expensive and has more resistance, when you can simply use tiny little wire and tiny little switch to tell a relay to open and close the circuit. Safer, too, to not have all that 'electricity flowing all over.
Another example, the starter on your car or truck. All of the power from your battery doesn't flow from your battery to your ignition, to the starter, and back to the battery. You have a solenoid that clicks when you turn the key forward and allows the current to flow directly from your battery to the starter. That is why you don't have 1/2" diameter wire running all the way to your steering column and then down to the starter.
Another aspect is load. You stock headlight wire is of a proper gauge to handle a certain amount of load. If you tap into that wire to run additional lights, you are running a much higher load through that wire. Probably more than that wire gauge was made to handle. Think about your house wiring again. You have many circuits because it is only safe to run so many amps through any one circuit. That is why you have circuit breakers or fuses. To prevent you from pulling too much load through the wiring. The fuse pops or breaker trips before you burn up your wiring. Say you have 4 outlets on one circuit and decide to tap into that wiring and add another 4 outlets. You can plug in more things so can potentially draw way more amps through the wire than it was designed for. In that case, your circuit breaker would trip way more often, which saves your wire, but what if you didn't have the circuit breaker or put in a larger so it didn't trip as easy. Now you would be overloading the wiring. The same is true of your bikes wiring. It is better to create a new circuit, with it's own fuse, rather than tapping into existing circuits pulling power for accessories through that existing circuits fuse and wiring, which may be undersized to handle the additional load.
