Just lost the use of radiator cooling fan on my mk6 1.8 16v escort ghia, causing the engine to overheat.

I think i have discovered the correct sensor/switch connected to a coolant pipe underneath
a short right angled air intake pipe which i have temporarily removed
Does anyone know how to test or bypass the temperature switch at the source?
How should I test if the fan itself is not kaput?
When disconnected from the switch, The loom end has 4 wires. The terminals are marked 1 to 5 with no connection to terminal 2. if i bridge the switch at this point, surely this will activate the fan?
Not sure how to discover which of the connections when bridged will allow the fan to operate.
Note: If I disconnect the switch and run the engine - the fan does not operate either, but I'm not
sure if it should anyway ?












