The main coolant t/stat near the block. I've replaced it already with the Ford original spare and it's the right one- the orange connector facing towards the front of the car definitely controls the guage. Perhaps the rad sender/switch acting up will make the ECU think the rad is cooling the engine well enough and therefore won't turn the fans on? Kinda fishing in the dark here...

I think the rad switch is the last thing to try. I mean, I've replaced the sender, replaced the t/stat (what a horrible mucky job that was when we started flushing with a hose) and checked that the fans actually do work.

I guess the very last course of action is to rig some sort of b***** switch into the cabin so I can flip them on at will, unless anyone has any bright ideas.

This is true- we're going down to Devon in July from near Kent and I was kinda concerned that the old girl will overheat in that weather if we get stuck in traffic. I suppose I could just jump out and pull the ECU sender cable to force the fans on or something though if it gets too hot, but I can't help tinkering!

I'll try a rad sender and report back. If nothing else, we did give it a damn good coolant flush and it really needed it, so that's something. Cheers :)

Edited by PhilG on 17/04/2011 at 14:54

Yeah I'm not sure what happened to it more than a year ago- my brother had it for 10 months and I bought it at 112k on the clock and while it's mechnically sound, I think the previous owners had an approach of "top up the levels before selling it" which means it's just running on a mixture of water and rust with a bit of antifreeze. It's on a 50/50 mix of the proper stuff now, but it took a good few minutes of flushing to get the water clear. He did at least change the oil every six months.

The thermostat was a delightful rusty-orange colour and sticking too.

Anyone? I can't seem to get a straight, logical answer out of anyone I talk to :-/

Thank you. Can you suggest anything I can try apart from sender and thermostat?