The diagram shows a typical wiring diagram for the Pro or VTX (or earlier NCC) series controller for use with two push-buttons.Note that the diode marked 'Diode' must be fitted or reverse will not work. Any diode will work, e.g. 1N4148.
Note that it is very similar to the standard wiring, the only difference is that yellow is now used as the common for ignition and reverse lines rather than white. Please see that page for additional wiring hints.
Of course there are many options available: we show a two push buttons but this can just as easily be a 3 position (centre off) toggle.
Undervoltage cutback on the Pro is a 'user option' which is enabled by fitting the resistor (shown bottom left) in the ignition (white) wire.
Battery condition meter can be added: you will have to connect it from the yellow wire rather than from the white and it will therefore be permanently on. If you want to switch this off you will need a third switch in the yellow wire.
All these bits are illustrated in our accessories catalogue.