I was hoping someone could assist me. Recently a blew a heater hose and determined that the engine cooling fan has stopped working hence overheating the coolant. I have done some initial checks, tested the fan - works, tested the relay - works (earthed the yellow and white/yellow lines).
I am not sure how to test if the temperature sensor works (temp gauge works on dash), or if the ECU is causing this issue.

In the meantime, I have the fan set on constant running, to get me to work and back until I can resolve this problem.

Can anyone shed some light on what could be the cause?

Many Thanks