Focus stalls when cooling fan cuts out

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Wed 25 Jan 2006 17:26
Focus stalls when cooling fan cuts out - Lotus mad
Hi all, here's an interesting one for you. My father has a Focus 2.0 Ghia, 1999, and its started to do a strange thing. When the radiator or A/C cooling fans (not sure which) cut out it stalls the engine if its idling. Very strange problem. I've searched the archives but only found a couple of articles on cooling fans etc being on constantly, nothing like this. Any pointers will be much appreciated. My father seems to think when the cooling fan is running it ups the revs slightly, so could be related to idle control somewhere.
Cheers, Jonathan
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Wed 25 Jan 2006 23:36
Focus stalls when cooling fan cuts out - Pete M
Sometimes (like on my Jag) there is a diode in the feed from the A/C or the water temp switch, as either one can activate the fan. What you don't want is for one to affect the other, so the diodes (electrical one-way valves) prevent current flowing the wrong way. If one of these fails in the short circuit position, it can kill the ignition when the fan turns off. Re-reading your message, implies that you have separate fans for each function, so I may be barking up the wrong tree. Still, you never know!
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