Join Date: Apr 2005
Location: SW Washington State
If you want to run a relay the following will help but the easy way is to use the wire behind the radiator, it is already only hot when the key is on.
Buy a 4 pole relay from the auto parts store, you'll find them in a blister pack for under $5.00 in the driving/fog light section. Run a fused hot lead and a ground wire to the relay. Connecting the hot side from the battery to the terminal marked 30, run the ground to #86 (you can run the ground wire from the grip heaters to this same terminal). Terminal 87 will be the hot lead to the heated grips or any other item like an accessory power box. And finally connect the terminal 85 to a power source that is only on when the bikes key is on.
Connect your ground directly to the battery not to the frame. Use a gauge of wire approprate to the load being drawn, use at least the same gauge or larger for the wiring to and from the relay that is used by the grip heaters. A smaller guage is an invite to circuit problems and or melted connections or possibly a fire.
So what happens then is when you start the bike or turn on the key the hot lead at 85 energizes the relay, sending power out of 87 to the grip heaters or whatever. If you have a 5 pole relay, the terminal marked 87a will be a hot connection when the relay is not enegized and can be used to power some item you want to use when the bike is not running, like a tire pump run this terminal to a seperate output device like a cig lighter, or powerlet.
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