This is why I would like to know the resistance three wires abnd the capacitor terminals. I have a theory that the blue wire connects to the jubction of the two windings via a thermal fues which has gone open circuit.
I am trying to get evidence to see if that theory may be correct.

Les

So that means I have to scratch the surface of cap wires and check the resistance between them right?

 

Sounds like the capacitor is connected to a winding maybe?
Here is a common fan PSC motor.

View attachment 310528

Here's an inside picture.

 

OK, so can you identify the colours that are connected together under the insulation sleeves?
Also the pair the cap is connected to?
Is it possible to gain access to the terminated ends?

 

OK, so can you identify the colours that are connected together under the insulation sleeves?
Also the pair the cap is connected to?
Is it possible to gain access to the terminated ends?

I'm afraid if I tried to check under the insulated area that I will damage any connection.

But I can scratch wire rubber connecting to the cap and contact them with meter probes.

White and Purple wires are the ones going to cap terminals.
So what do you want me to do with cap terminals?

 

The idea is, is to identify the three leads that are shown in the first diagram, as in post #20.
Once the centre connection for the two windings is known, it should be easy to figure out the rest.