On the wiring diagram, look at the PTO switch. The red wires have power when the keyswitch is in the on position. When the PTO switch is in the on position, power from the red wires goes thru the PTO switch contacts and into the blue wires. The light blue wire goes to the electronic control module so it knows when the PTO switch is on. The dark blue wire goes to the electric clutch to power it for engagement.
The electronic control module is the brains of the machine safety circuits.
