This is a 49 1/2 ton. I have always assumed that the switch is turned to the right for ignition (clockwise) and to the left for accessory (counterclockwise). I can't tell for sure because in it's current operation, the ignition terminal is hot in all three positions. I'll do a bench test tonight. When I bought the truck, I only drove it about 5 miles before it went in the garage for restoration. I keep thinking that the operation of the switch was odd in the beginning with the original 6 volt system but you could shut the engine off with the switch.
