I acquired a used WP32 wheel pilot, and the junction box and cable were not included. Can anyone help me figure out which wires coming out the back of the keypad are the NEMA signals? The choices are white, yellow, blue, and green. These four wires go to a connector block inside the keypad case. The standard cable may use different colors by the time it gets to the junction box...the manual doesn't include this information.As an alternative, does anyone know how I might recognize the Nema signals using an oscilloscope or voltmeter?