I connected mine under the seat. There are wires that go to the rear brake light switch, one live when the ign. is on. The ampage is low, but so was the drain from my grips (some grips are higher). Anyway connected using a small connector from Maplins, just lay the "source" wire in one side and the new one on the other side then snap shut, no need to cut anything. Here is a pic, bit fuzzy I'm afraid but it was very cold out there. The connector is the light blue one at the top centre of the pic, the red wire goes off under the tank to the grips switch.

Hope this helps. :NEW29