if i wire in an aftermarket starter solinoid what should be done with the wire for the ballast resistor ? does it need positive or negative fed to it ?
The second spade from the standard solenoid ("I" terminal) is a "feed" (White/Purple wire). It is a ballast resistor bypass, so it's purpose is to send all available battery voltage directly to the (6V) coils as it gives the coils a temporary voltage boost when the starter motor is operating.
If your Commando is still positive earth and using points ignition then there may be some benefit in using the bypass wire during electric starter operation (stronger sparks).
If your Commando has any type of electronic ignition fitted instead of points (and ballast) then the White/Purple bypass wire should
not be connected to the solenoid and/or ignition coils.
