I just did it. Easy less than an hour to do. I tapped into the red/black using this http://www.posi-lock.com/posiplug.html and then directly to the positive post on the battery.
The hardest part was getting enough wire to tap into. I gained between 1/2 and 1 volts depending on revs.

Bill. "I spent a lot of money on booze, birds and fast cars. The rest I just squandered." -George Best