Frank @ Triumph-Online also sells a Hella plug to cigarette lighter socket lead. Saves chopping all your accessories up. I've put a cigarette lighter socket on all my 12V bikes (so that all of them) and my charger accessories (phone, sat-nav, helmet bluetooth) move from bike to bike.What you need is one of these.
The ST comes from the factory with a power outlet already installed behind the left cowling. It most likely would work?I have a Triumph Tiger 955i 2003, can any one help me find a power take off plug to attatch to a small 12v compressor to the power take off point just under the petrol tank.