Ford Super Duty Upfitter Switches – Blue Oval Trucks Auxiliary 1= Red wire. Auxiliary 2 = Blue wire. Auxiliary 3 = Purple / Orange Wire. Auxiliary 4 = Black wire. Above you can see where I took the red wire (looks orange) and connected it to the white wire that Ford provided to go through the fire wall. The wire comes out at the top of the firewall in the engine compartment on the drivers side.