Air con not worked for a year on my Fabia 1.4 2000 model.

It

Interesting how you powered up the clutch with 12v, it doesnt have a clutch. The compressor is constantly driven.

The air conditioning system has comprehensive self diagnostics, id get the fault codes read off.

There is more than one explanation of how to do the temp sensor, all you need to do is search,

When I disconnect the plug from the pump (opposite end to the pulley) and measure the resistance it

Sorry cant read your colour text, i'm using the fusion forum skin.

The compressor is driven constantly and there is a duty cycled solenoid which varies the load on the compressor. This is controlled by the climatic ECU. Thing is this system works on 5v so whacking 12v down it might not be the best idea.

Don

The duty cycle is turned on and off, this signal is used to control the actuation of a solenoid in the side of the compressor. This solenoid is attatched to a wobble plate inside the compressor. The front pulley is allways spinning and depending on the position of the plate varies the load on the compressor. Even when it is 'off' the duty cycle is at 2% and keeps the compressor running. This helps the system keep gas circulating and stops seals drying out.

Very helpful to have that diagram. It explains what the sensor under the bonnet is - item 10 on your diagram. Do you have the electrical diagram showing how the sensors are connected?

The click I heard when applying 12V must be the solenoid/regulating valve running to max pressure end. Maybe too high a voltage, as you say.

I guess I could fool the aircon into working well by applying a variable voltage on the pump solenoid in range of 0 to say 5volts at up to 0.2amp. More voltage for cooler temps. Variable steady voltage isn't quite same as a PWM signal but should have the same effect on the solenoid. But not quite clear if it

Applying 5volts to pump connector from a mobile phone charger that plugs into the cigarette lighter socket does the trick as a temporary fix. Should disconnect it occasionally as might otherwise be possibility of icing up evaporator.