Hi everyone,

I have a 2012 Fiesta S1600 and am trying to find confirmation of what temperature the cooling fan is supposed to kick in at - I recently changed the coolant & am wondering if I've done something to cause a problem as I don't think mine is working properly, but after hours of trawling the web I can't find any definite idea of when it should come on.

I took it for a 15-20 mile drive the other day, both Forscan connected and the diagnostic / "secret" menu activated to show the coolant temp - reached a steady 82-84 degrees whilst driving. When I got home I left it running & watched the temp / waited for the fan to start but it never did. I let it get to about 103/104 degrees before 'getting scared' & turning it off.

I tried to check as much as I feel confident doing, based on what I've read online:-

1) coolant level seems fine - hasn't dropped & I'm not noticing any signs of leakage in the driveway. I was worried about possible airlocks, but I'd bled the air via the small valve at the top of the radiator when I re-filled the coolant, and when I squeeze any of the hoses I can see coolant pushing through into the expansion tank so it all seems to be circulating ok(?)

2) checked the fan fuse - ok

3) tested fan relay with 12v supply & multimeter - it 'clicks' as expected & give a continuity reading when activated.

4) tested voltage at the relay slot & this is ok, also 'jumpered' the connections in the relay slot & the fan came on straight away (it also runs fine with A/C so I already knew the problem wasn't the actual fan or motor).

5) the cabin heating works fine.

6) all hoses appear to heat up as & when expected.

7) oil filler cap shows no signs of 'milky' residue (as some sites have suggested if there is a coolant leak into the engine).

Also, there are no DTCs show when checked with Forscan (or within the diagnostic menu).

Anything further starts getting a bit too technical for me!

The only other things I read about are either the thermostat or ECT sensor, but surely if the thermostat wasn't working properly then the bottom hose wouldn't get hot? (which it does after the temp hits 82 degrees & above). I'm not sure how to test / confirm problems with the ECT sensor, is it possible to test with a multimeter whilst fitted to the car?

Could it be that I am just not letting the car get hot enough to cause the fan to kick in? I've not had any warning lights or experienced any signs of overheating yet, but I'd like to put my mind at rest if posible.

Thanks for any help!

Andy

The thermostat is designed to open at 82c so that's working perfectly.  

I can't give you a definite answer on fan temps, though I seem to remember it's about 107c on these, they do run hot.  I reckon you were just short of the fan cutting in on your idle test personally.  Did you notice the fan cutting in more often before the coolant change?

Hi Tom,

Thanks for the reply.

The fan did used to come on occasionally prior to the coolant change, bizarrely I only really noticed it when I would pull up at home after work, then reverse into my parking spot - it would sometimes come on as I went into reverse (not sure if that has any significance?)

The majority of my journeys are short ones for work - basically I'm based at home & travel to local schools, so I might only drive say 5 miles, then the car's parked up for 1-2 hours (or longer), then I'll then driving another 10 miles to a different school, etc. Also it's mainly rural roads & no city centre traffic so it's rare that I end up standing in traffic for any length of time. As a result I can't really recall it coming on during a normal days use.

One thing I discovered yesterday though - I was having another look at it (checking for airlocks again, etc) and let it get to 99 degrees before deciding to turn it off. Just before cutting the engine I put the AC on to get the fan going & pull the temp down a bit, after it dropped a couple of degrees I turned the AC off only to find that the fan kept going, until the temp dropped to 82 degrees at which point the fan stopped.

It's almost as if it doesn't know when to start working, but once it's working it knows what temp to cool the engine down to before switching itself off(?)

Anyone ever experienced anything similar?

There's a ford dealer near one of the schools I visit so I might pop in & see if they have any idea about the starting temp for the fan.

The fan shouldn't stay on until 82c, that's way too cool, the stat will be closing by that point.  It should be cutting out around 92-95c roughly.  It does seem like you've got a fan control issue, especially with it coming on in reverse as well, possibly a loose connection somewhere. I'm not really sure what to suggest tbh, though I don't think your coolant change will have affected it.  

Whilst the subject of Fans is about, im not sure if my Mk 7 ZS is working correctly or not.

When you start the car, the AC automatically comes on. Is that right, and when it does, the cooling fan is on instantly too.

When i turn the AC off, pretty much straight away, the fan stays on a for a minute then turns off.

Is that right or is there an underlying issue?

Thanks

2 hours ago, WoldsWarrior said:

Whilst the subject of Fans is about, im not sure if my Mk 7 ZS is working correctly or not.

When you start the car, the AC automatically comes on. Is that right, and when it does, the cooling fan is on instantly too.

When i turn the AC off, pretty much straight away, the fan stays on a for a minute then turns off.

Is that right or is there an underlying issue?

Thanks

I'm guessing you've got the air direction set to windscreen?  Set it anywhere else and the AC shouldn't keep coming on automatically. 

On 5/7/2019 at 11:42 AM, TomsFocus said:

I'm guessing you've got the air direction set to windscreen?  Set it anywhere else and the AC shouldn't keep coming on automatically. 

Correct!

To be fair i only discovered that was the issue on Sunday when i had changed the direction of the fan to feet!

Cheers

Hi there, did you managed to find out? I have the same here. Thanks in advance! 

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