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Large MPVs -- Ford Galaxy / VW Sharan / SEAT Alhambra: => Ford Galaxy / VW Sharan / SEAT Alhambra => Topic started by: bobetski on May 12, 2012, 05:32:00 PM

Title: Main fan permanently on
Post by: bobetski on May 12, 2012, 05:32:00 PM
Hi to everyone on the forum.

I have  a potential problem in that the main radiator fan is permanently on when the engine is running.  If you switch on the engine the fan stays still for around 5 seconds then ramps up slowly to full speed and stays on until engine stops.  Ihave checked fuses and first layer of relays (can't get to the ones further back without removing a black frame - any ides?)and air conditioning turned to off but nothing seems to be able to stop the fan running.

unplugging the radiator thermostat does nothing.

The car had a fault codes when hooked up to a Delphi diagnostic kit.

17764 - Engine cooling temp switch open/short to positive - Intermittent
18080 - Cooling Fan 1 short to ground/open - Permanent

Anybody had similar issues?  Should the fan be on permanently?  I am guessing if not then I am getting unnecessary load on the alternator permanently which is not good.

Thanks for any advice/ideas in advance

Title: Re: Main fan permanently on
Post by: Mirez on May 12, 2012, 06:34:31 PM
Hi and welcome to the forum, have a look in the reference library: Link (, specifically Here ( for info on how to get to the 2nd and 3rd layers.

The fan definitely shouldn't be permanently on, the two fault codes are the ones to go on. Have you got two fans? The 2nd code would indicate that you have and that the first fan needs to be replaced. The first code is the source of your fans ramping up to full tilt, since the temp switch is telling the ECU the car's overheating.

**Edit 23/12/15: Also read:
Title: Re: Main fan permanently on
Post by: bobetski on May 15, 2012, 09:34:27 PM
Thanks for the information.  I was a little baffled as I am pretty sure I only have 1 fan.  Will check over this weekend weather permitting.  I would have thought removing the temp sensor wire would have solved fault 1 issue or do you think the sensor closes when the wire is removed and runs the fan permanently? Not sure if the fan is ecu controlled or simple switch on the radiator sensor? so was expecting removal of plug on sensor to stop the fan but it did nothing.

Will let you know when I find out more info and thanks for the links to access lower relays.