Yes, the fan motor will run. But the problem is that there is never any volts on that circuit - and I've let the engine temperature get to 40-50%. In addition there's no doubt that the engine is running rich (exhaust tail pipe not clean, and the cylinders would appear to be coking up as there is now evidence of pre-ignition if I just have too much accelerator pedal in low revs, and it certainly wasn't doing that six months ago) so, to me, that suggests that ECU just doesn't know how hot the engine is. The question is how easy is it to diagnose - hence my comment about checking the wiring because that is the next link in the chain, so to speak.
