Adding a relay to provide ignition-switched accessory power

Originally, I added several power outlets and a dual control Heat-Troller to my 2003 Yamaha FJR1300. Then I realized someone could turn on my heated grips when the bike was parked, and run my battery down. So I decided to add a relay tied into the ignition so that power to the heated grips and accessory power outlets would only come on when the ignition was on. [My first try at this resulted in hooking into the wrong wire, a fault uncovered by Tom Barber. Thanks, Tom!]

I also wanted to put the fuses somewhere more accessable than behind the panels where I currently had them. Here's how I did it:

First, I added a waterproof fuse to the unswitched power outlet in Panel "D". This is a nice fuse carrier I got from Jastek Engineering which uses the standard automotive blade type fuses. It mounts nicely such that it is accessable without taking off any of the panels.

Here is the same type fuse I added to the switched power on Panel "A". This fuses the dual control Heat-Troller which controls the heat for my Gerbings heated jacket liner, and my Dual-Star heated grips.

I added this 30amp relay to switch the power for the Heat-Troller, heated grips and switched power outlets. I got it from a NAPA auto parts store (part number "AR204 ACCESSORY RELAY"). In the photo above it is temporarily cable-tied to the black metal dash frame. I permanently mounted it a few inches lower, with cable ties, to the same frame member.

For power to the solenoid side of the relay, I tied into the green wire with the blue stripe which powers the headlights. The wire is in the bundle identified by the red arrow in the photo above, and is found directly underneath the dash's SELECT and RESET switches. This has the advantage that the power comes on only after the engine has started, rather than simply with the ignition switch itself.

Here's that heavy-gauge green wire, with the blue stripe, showing where I removed the insulation so I could solder a small-gauge wire from it to the solenoid side of the relay. The other connector of the solenoid side of the relay goes to ground. Refer to the drawing below.

There were no directions with the relay, but this simple schematic was printed on the side. A friend with an EE degree helped me figure out how to hook it up. The fat red wire in the drawing is the power from the battery that is switched on/off to the Heat-Troller. The small red wire comes from the green/blue-stripe wire described above.

I also chose not to install a power distribution block, as with the setup I use I only needed to attach two wires to the battery's positive terminal. I do think there is a need, however, and a market, for a compact power distribution block for motorcycles which is fused, and offers both switched and unswitched connections.

The final result was very satisfactory! The installation looks neat, only the fuse carriers are visible. The power comes on after the engine starts, and I can hear a tiny click from the relay if I listen carefully for it. Now I don't have to worry about accidental battery drain. In the photo above the numbers indicate:

  1. Heat-Troller knob for two power outlets (not shown) used for a Gerbings heated jacket liner.
  2. Heat-Troller knob for the heated grips.
  3. Fuse for the Heat-Troller
  4. Fuse for the unswitched power outlet.
  5. Unswitched power outlet for tankbag power.
  6. Momentary contact switch for hidden garage door opener.

The unswitched power outlet (#5 above) in Panel "D" was a personal choice, as I use it to power my tankbag which contains a Valentine One and a Garmin GPS III+. I never leave the tankbag on the bike, so power drain isn't an issue there. Plus, I can use it to trickle charge the battery with a Battery Tender during the winter months.

Copyright © 2002, by H. Marc Lewis. All rights reserved.