Set Appliance State:

Set Multimeter to DC Volts Set meter to measure DC Volts
Ensure NO demands
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Measurement:

Measure the DC voltage between pin 2 (Red) on
connector X3 to a suitable earth point.
Expect approximately 12.7 vdc.