Non Land Rover question, Its a Ford

[BigA]

Here is one for all you helpful mechanics.

I have recently replaced the clutch and bearing in the wifes Ford Focus 1.8TDCI. I wont go into that, i just hope i am not doing another one in a hurry.

Now, since its all been back together, all is running fine (i was surprised there) but the cooling fan is coming on straight away from cold, and after about 30 seconds kicking in full power?

I have checked that i plugged in all of the great number of connectors i had to undo. I have tried the HEC test and i dont get any DTC errors, and when i just ran it again, as far as i can tell it thinks the engine temp is 16C. I did not disconnect the head temperature sensor when doing the clutch (about the only thing on that side of the engine that was not disconnected) and as far as i understand this is the only temperature sensor used, as the fan is controlled from the ECU. I have also checked all the above with the heating and air con off.

Any pointers will be greatly appreciated as always, as this has now got personal. It could be worse i guess and the fan not coming on at all, but i would just like it to be correct.

cheers for now

Andy

[Sharpshooter]

Well. Very strange. Firstly the temp sensor will think it is 16c as this is probably the ambient temp.

Secondly, my stepdad called me a while back to say the same thing with their Shogun. As soon as you turn it on the fans running. Went round, and turned out to be the Air Con fan.

Now, as you have managed to change a clutch im assuming you have some mechanical knowledge, and had eliminated that. Ill have a look on my autodata and see if it comes up with anything.  :lol:

[bilge rat]

i'd guess at ambient air sensor too. usually around the front bumper area of the car , not knocked it off without knowing . ?. cant think of anything else..alan

[BigA]

Now, as you have managed to change a clutch im assuming you have some mechanical knowledge

ahh, you dont know me  :lol: heh heh. As far as i can tell the aircon fan is not kicking in. Its just the cooling fan, then either spinning up faster, or air con coming on also, but i am sure its still the one fan.

bilge rat
  I thought the same thing, but i may be well off the mark, but the Focus fan is controlled by just the one sensor via the ECU. I certainly cant find any more, but that doesn't mean they are not there.

Thanks guys for replies so far,

Andy

 

[Sharpshooter]

Turn the Air Con off. What happends then?

[BigA]

Turn the Air Con off. What happends then?

tried that, air con and heating off altogether, as i found that it turns the air con on when set to demist, but no difference. I have tried with the temp sensor disconnected, no change, checked all connections again today, disconnected each one and reconnected to make sure they are all plugged in ok. The only thing that makes a difference is to unplug the fans lol.

I have searched the web, but only results i get is for fans not coming on at all. Wouldn't be so bad, but Abi (the wife) didnt notice it until i pointed it out, and is now going on about it lol.

[bilge rat]

just a daft thought but make sure you have all the codes radio / alarm e.t.c. but when we had trouble sometimes with modules we used to disconect the battery for a few minutes then re connect . ued to work with some marques . but was never fan related ...

[solihull-mick]

Ive had this a few time in the past, if the ECU for the engine sees an open curcuit or incorrect resistance from the fan switch, it will put the fan on all the time, its a default mode of the ECU to protect the engine, check the sensor wiring, is it plugged in? hope this helps

[BigA]

just a daft thought but make sure you have all the codes radio / alarm e.t.c. but when we had trouble sometimes with modules we used to disconect the battery for a few minutes then re connect . ued to work with some marques . but was never fan related ...

Tried this one today, hod the battery disconnected for about half an hour, as some of the cables needed re-routing as they were annoying me, but unfortunately no change. Got told off for not re setting the clock though  :doh:

Ive had this a few time in the past, if the ECU for the engine sees an open curcuit or incorrect resistance from the fan switch, it will put the fan on all the time, its a default mode of the ECU to protect the engine, check the sensor wiring, is it plugged in? hope this helps

Unfortunately i have a nasty feeling that this is the problem. I re checked all the plugs yesterday. As far as i can tell everything is connected, and i unplugged and re connected them all again to check. There is a resistor on the fan shroud, that i have seen mention off a few times on the web. So i guess i may need to check this.

I am glad i usually stick to my old non electric 300TDI, At least if i miss something on there, i usually have the bolts or big bits of metal to show it 

[carbore]

Now then.....

...as its your wifes car are you sure it was not happening before the clutch job especially as you said she diddnt notice? if so....

It could simply be the sensor is faulty, maybe it reads 16c by defualt. Try testing its resistance, dead short often means its duff, but you need to find out the correct value beofre testing as it may be volts based etc. Alternativley if the sensor is not too expensive and not in a place where its a pig to change, just replace it, there is no point spending too many hours researching/testing when a new part will rule it out in a moment.

It could be a faulty wire, try remking (a few times) all the connections you broke as it could be a bit of corrosion side a connector some movement may re establish the connection. Also the wire in the connector could have been strained, so try wiggling the wires around and looking at the output to see if it jumps/etc.

Possibly if it is clutch change related, you have not conencted or got a bad earth possibly if you greased bolts etc. Check any earth straps you made and ensure The have continutiy.

My very brief experiance of DTC codes is that they are not 100% relaible in ruling things out due to how the ECU "sees/interprets" various signals etc.

Let me knoe how you get. on

[mobi]

i take it there is a plug on the wiring is it pluged into the right one, some cars have 2 plugs close to each other one of witch is switched and one is constent live.
it's there as a get you home if you are over heating.

[BigA]

i take it there is a plug on the wiring is it pluged into the right one, some cars have 2 plugs close to each other one of witch is switched and one is constent live.
it's there as a get you home if you are over heating.

The temperature sensor is the one plug on that side of the engine that wasn't unplugged when i did the clutch and as far as i am aware there isnt another plug/socket nearby but i will take a look.

...as its your wifes car are you sure it was not happening before the clutch job especially as you said she didnt notice? if so....

Had the same thought myself, and to be honest i dont know

It could simply be the sensor is faulty, maybe it reads 16c by defualt. Try testing its resistance, dead short often means its duff, but you need to find out the correct value beofre testing as it may be volts based etc. Alternativley if the sensor is not too expensive and not in a place where its a pig to change, just replace it, there is no point spending too many hours researching/testing when a new part will rule it out in a moment.

I have thought about this, and need to check on the price of the sensor. Its a bit of a pain to get too, airbox and battery tray probably need to come out again, but otherwise its screw out and new one back in. Wanted to see if i can test it first.

It could be a faulty wire, try remking (a few times) all the connections you broke as it could be a bit of corrosion side a connector some movement may re establish the connection. Also the wire in the connector could have been strained, so try wiggling the wires around and looking at the output to see if it jumps/etc.

The wire being strained is a big possibility, it was very near where the hoist was lowering the gear box, and may have got caught. As it makes no difference unplugging the sensor all together, this could be a good bet.

Possibly if it is clutch change related, you have not conencted or got a bad earth possibly if you greased bolts etc. Check any earth straps you made and ensure The have continutiy.

I have tried to check all these, but as far as i remember, and have checked, no major earth connections were removed, but you never know.

A few more things to check. Will probably be the weekend now before i get a chance again. Thanks so far for the helpful advice from all as usual.

Andy