I have a relay which is activated by the rear light circuit. This gives the power to the Oxford grips and heated jacket,,,,,,, and GPS. Means that you cannot forget to switch off these appliances. The realy is suitable to switch 30amps and works well with these extras. Not too difficult to do but you do need a good soldering iron, mixed terminals and heat shrink tubing, available from Halfords. Hope this helps.

I too am coming up for my 6000 mile service, will keep this in mind.