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Filtering by Category: "power"

Switched (and Unswitched) Power Options

Tomas Perez

Power Distribution Box

What do you have to do to provide power to an accessory that you want to add to your motorcycle.  This is what I did on my R1200RT but the same principle applies to nearly any other motorcycle.

Switched - This means that power is supplied whenever the key is turned on.  Power is off when you switch your bike off.  It's nice because you don't have to worry about turning stuff on and off.

Unswitched - Power is always available regardless if the bike is running or not.  The caution here is that whatever you are powering could drain your battery but there are a number of times you may want to use this method.

Let's say you want to add a heated seat to your bike...

There are two ways you can provide a switched power source to your heated seat.  The cheaper (although not as nice or versatile solution) is to power a relay via the marker light wire.  The marker light is the small light at the corners of the headlight.  FYI: the marker light is really a parking light that is required in some countries.  You might be able to use the headlight wire also but I tend to stay away from those because of the CAN bus system.  When you turn on the key the light goes on and at the same time it energizes the relay that turn power on for the seat.  Bike off and the relay drops power and the seat is no longer receiving power power.

A better solution would be to use a power distribution box.  There are several in the market but I use the FuzeBlock.
Link: FuzeBlock

One small box kills about 4 birds with one stone.  This solution allows you have switched and unswitched power available to multiple devices and in addition allows you to fuse each one separately.  I use mine to power additional brake lights, XM radio, GPS, power amplifier, and SAE power plug.  I also have a direct connected (fused) SAE to the battery for heavy duty stuff.

Once you have installed a power distribution panel to your bike it makes it easy to add powered options.  In addition, you have the option of using switched or unswitched power.  You can even have double switched power to a device.  For example, let's say you want to add a driving light that only turns on with your high beam.  These types of lights normally come with a switching relay that is controlled by the high beam wire and directly connected to your battery but  I would still use the power distribution box to supply power to the switching relay.  This is a case where you could use either switched or unswitched power to the relay since the relay is only switched (powered) whenever the high beams are turned on.

When shopping for a power panel be sure to look into the number of circuits supported, maximum current per circuit, and total current supported by the panel.  Also are the circuits switched or unswitched.  You might be able to live without unswitched circuits but at times that can be very handy, i.e., map lights, cell phone chargers, camp lighting, etc.