OK right, so the cable from the NVR seems to be 4-core. If we number the three white terminals in a row 1 - 3 we have:
1 - brown switched line from NVR > two blacks into motor
2 - grey switched neutral from NVR > white into motor
3 - black switched line back to NVR hold coil via thermal protector > thin blue into motor
So the first circuit that we should see is zero ohms between 1 & 3 to enable the NVR coil to operate.
Then, we should see the motor main winding between 1 & 2.
The auxiliary winding and switch we have to measure by breaking into the capacitor leads but if there's nothing happening then we begin with the main winding.
What are the resistances 1-2, 1-3?
Terminal screw heads were not reliable (no clean contact - dust, age corrosion etc) so to establish the correct reading I cleaned the crimped brass end fittings on each wire with wire wool and then reinserted into terminal block. Then touched the respective ends with thin gold plated probes.
1-2 = 0.3 Ohms (initially fluctuated between 0.3, 0.4 and 0.5 Ohms - settled quickly at 0.3)
1-3 = 0.0 Ohms