Hi guys

Really hoping you can help me.

I drove our Focus back from the tyre shop yesterday and parked up no problem. When I then went back out roughly an hour later I could hear the engine fans on which I thought was strange. I then noticed I couldn't unlock the car with the remote key and found the battery was dead. I then disconnected the battery to stop it and since reconnecting it, I found the relay/fuse F6 Aircon engine cooling stops the fans blowing if I remove it. I tried to replace it with another 30amp fuse from the box, but it still continued.

Now the aircon is off in the car and actually has not worked for a few years. It might have been on the windscreen dial though (which I understands turns on the aircon even though the AC light is off). Yet I have now turned the heater dial to 0 so it is off, but the engine fans come on straight away as soon as I replace the relay F6 with the engine completely off.

1.) Has anyone come across this before and know where the issue is?

2.) Can I leave the relay/fuse F6 completely disconnected and then jump start the car to drive it? Ie does the fuse only control the aircon which I will leave OFF or is it not that simple and I will risk the car overheating or worse?

Much appreciated for any advice or tips?

Cheers,
Ant

 

Okay I managed to jump it earlier leaving the fuse in and fans were really noisy again. I let it run for a good while and*took it for a quick loop around the block and seemed to drive fine, but I noticed this temperature gauge on the left in the picture below didn't move at all from the bottom the entire time. To be honest I am not the most mechanically minded, so not sure if this is normal as it is my wifes car usually.

Anyway after turning the engine off the fans continued to run and I have removed the fuse for now not to kill the battery again.

 

The fans are needed for normal engine cooling.
The temperature was low because the fans are on and cooling the engine radiator, but shouldn't be.

You've probably got a faulty temperature sensor bringing the fans on when they shouldn't be on.

 

Thanks for replying mate, that makes sense. Can I confirm this is definitely the part:

http://www.eurocarparts.com/ecp/c/Fo...6d3b193&000572

Is it easy enough to fit?

 

Check the underbonnet air temperature sensor, it's a metal sensor that clips to the side of the battery box. Unplug it and see if the fans stop!

 

My money would be on a faulty fan relay which has stuck on. Had this in the wife's fiesta zetec s.

 

Thanks both, away with work until tomorrow now, but will at least check the under bonnet temperature sensor tomorrow and thanks for the tip on the faulty fan relay which I will also investigate.

 

Hi Richie, just to double check is this the sensor you mean in red?

 

No the one just above it, the round metal threaded sensor.

 

Thanks mate, I think that was the issue

I struggled to remove it earlier as it was belting it down with the wind and rain, but I cleared what looked to be a little bit of metal gunk with a knife and gave it a good wiggle and hey presto the fans are no longer running with the engine off. It seemed much quieter on a quick spin and I have checked it once since after 20 mins and still seems fine.

I am going to order a new radiator switch anyway to be on the safe side, but really appreciate the help from you and from everyone else (I was about to order a temperature sensor switch today as the next step).