Ground it to the engine. They recommend to a bolt from the clutch cable mount right there on the back left.
If not you may end up cooking it like I did......
Mines still in power commander limbo at their business in Vegas
2013 Victory Hardball - VM1DR cams, Lloydz filter, timing wheel, PCV-AT, 1/4 turn throttle, modified pipes
2008 Yamaha Warrior -Churchkey intake, V&H Bigshots
2007 Scion TC 5spd
1997 F150 -used to pull my car hauler
1989 Nissan Hardbody -absolutely indestructible
1968 Coupe Deville -all black, so nice