The radiator fan is not coming on when hot...However...

The system overall is working. If you switch on the Air con the AC ecu does switch the fan on and the two speed system works too.

It is simply that with the AC off the (Relay 1) does not receive an earth signal from the ECU when the engine gets hot.

Live data shows the engine temp rising to above 100C and there are no fault codes so I am assuming that the engine temp sensor is working correctly.

I would like to check the continuity between the Relay and the ECU but, although the ECU is easily accessible AUTODATA bizarrely (since it does provide the wiring diagrams) does not provide an ECU pin out making doing this rather difficult. (Tracing wires is not an option since I am colour blind, I need the pin numbers and numbering layout!)

Would anybody have such a thing (an ecu pin diagram)? (And has anybody ever come across ECU/Wiring issues before that might cause this fault?)