Module 2 This is the default module. It is active when no voltage is present
on the other wires.....that is usually use to protect your engine if a drivetrain part breaks..like a rpm pill 500 rpm above your shift points...

Module 1 Active when 12 volts are applied to the Red Wire....can be used for trans brake or line lock..I use this one for the line lock..limit the rpm in burnout...

Module 3 Active when 12 volts are applied to the Blue Wire. (3-Step Only)...again..can be used for trans brake or line lock....I wire this one thru the transbrake for controlling starting line rpm..

Note: If 12 volts are applied to the Red and Blue wires at the same time, Module 3
will be active....I wire the trans brake and line lock together..and use a diode to keep line lock from back feeding the transbrake with voltage...so the transbrake and line lock holding the front tires keeps car from rocking..you would want to set your starting line rpm on the blue wire...