Heated grip wiring

Bought a new 2010 DL1000 a few months back & had aftermarket heated grips fited at time of purchase. Dealer wired them direct to the battery instead of via ignition, so if I forget to turn them off at the control box (which I have done) - yep flat battery! Heard someone say there is a spare wiring harness from the headlights that could be used so heated grips turn off?? Can anyone point me in the right direction or a quick fix?