Do you have a power outlet under the seat ? If yes, connect the control wire to it's positive terminal.

 

Do you have a power outlet under the seat ?

I don’t believe so.

 

If you have one, locate the wire going to the center connectorand connect your control wire to it. The acc. connector turn on with the ignition and turns off 5 minutes after shutting the bike off.

 

Saw this pic in another thread. Is that method recommended? Looks a bit sketchy!

 

As long as it's well insulated, it's ok but I prefer the Posi-Tap connectors.

 

+1. I used a posi tap to that red/blue wire.

 

"So I’ve installed an accessory and have good power. The power unit is under my seat and has an accessory wire that the installation manual says should be connected to switched power so that the unit is powered on with the ignition."

Where/how is the power to you accessory wired? Directly to the battery or is it tied into the bikes wiring?

 

Where/how is the power to you accessory wired? Directly to the battery or is it tied into the bikes wiring?

Directly to the battery. It then has a third wire to connect to an ignition-controlled source.

 

so you need a trigger, then you can use the rear tail light run wire.

 

To answer the title of your thread "What is the easiest way to make power to an accessory ignition dependent?" it is to tap a keyed positive power source like a positive to the fuel tank valve or rear running light as others have stated a Posi-Tap

Here is a keyed power source on the fuel tank valve on Hexhead GS's that I use as a "trigger wire" for running aux components. The 30a fused relay is connected directly to the battery to power the accessory and the trigger wire is run to a keyed power sources when the ignition is turned on the trigger wire send voltage to the relay and pull in the contacts and completed the circuit allowing power to flow from the battery.

Here's a link to another post about installing aux lights and the OP needing a trigger wire.

Aux lights

Hi. 2009 r1200gs I am trying to fit front fog/aux lights. I have researched but can't find answer so any help gratefully received. I have a spare relay carrier next to starter relay which is for this purpose so I am thinking if I buy relay and plug in it is wired already for the job. But where...

www.r1200gs.info

 

Thanks everyone - I think I’ve got my answer(s)!