How to identify which Wiper Motor (2 speed or 3 speed) Should be on 75 Duster

a 3 speed wiper motor is wired directly to the motor (no connectors visible on the outside of the motor, just wires from the bulkhead connector into the motor) and a 2 speed has wires from the bulkhead connector to a plug (4 wires) that plugs into the outside of the motor. If you find the plug it's a 2 speed.