H4 Bulb Tabs, What Does What - Electrical

I am going to wire my HID's directly from Tinywads fuse box.  On the back of the factory bulb, there are 3 tabs, one horizontal and a left and right vertical.  Which tab in the connector that attaches to the back of the bulb powers what.  And which one grounds the bulb.  I am under the assumption that one of them goes on to power the high beam since the high beams come on with the lows after the switch has been flipped on the handlebar?  I want to be able to continue to use my high beams.  The ballasts are easy to wire, they connect to a positive on and a negative battery.  Do I need to jump a wire in the factory connection to retain the use of my high beams, or are they supplied with their own power and ground from the factory.  I need to wire a switch in line to the ballasts to power them up after the motorcycle is running.