Technical Cooling Fan Not Working

[leigh71]

Hi, i have a fiat stilo 1.2 16v 2002. The cooling fan is not working, i have checked the fuse and this seems fine, any other ideas would be greatly appreciated.

Many thanks
Leigh

 

[Dcthebear]

Engine temperature sensor most likely or the relay. Just check the fans blades spin ok and don't catch the surround first though but make sure the engine is off!

 

[StiloBoy]

Just out of curiosity, how do you know the fan isnt working? I also have a 1.2 and mine rarely comes on, pretty much never when driving, only occasionally if the car is left idling for a long time.

A copy of FES is pretty good, as you can spin up the radiator fan, slow and fast.

As above though, if you've got FES, do the fan test. If it fails I'd expect it to be relay. If it spins I'd expect fault to be temp switch.

 

[leigh71]

Great, thank you. The blades do spin but cant find the relay or temperature switch lol. I am a real novice.

 

[leigh71]

I left the car running and the temperature guage was on the red but no sign of the the fan coming on. I have only had the car 3 weeks so am very new to the workings of fiats. So sorry for being a bit vauge.

 

[StiloBoy]

F06 and F07 in the fuse box by battery control low and high speed fan. Can't see a relay mentioned in manual, so maybe it's just the maxi fuse.

I'd make that your first port of call, and I'd recommend not using the car until you get the fan working, running engine in the red can cause all mater of pain for you, failed head gasket, warped head etc.

 

[Davren]

Low speed engine fan is supplied via fuse F6 (30Amp), relay T6 and resistor O10. High speed fan is supplied by Fuse F7 (50Amp) and relay T7. Both fuses and relays are in the engine compartment fuse box.

Signals to switch the relays are sent from the engine management ECU M10 which gets engine temperature information from the engine temperature sensor. I believe the temperature gauge is controlled from the same sensor, in which case, if the temperature gauge is working the sensor must also be working.

The earth point C1 for the fan is one of the smaller black cables attached to the battery negative terminal.
.

 

[Stilo Nutter]

Is that info the same for the JTD Davren?

 

[Davren]

Is that info the same for the JTD Davren?

No... it's the same as above for all engines except the JTD, 1.8 and the 2.4.

The JTD, 1.8 and 2.4 engines have an expensive ECU to control fan speed instead of a cheap resistor. The ECU M150 is supplied only via fuse F6 (now 50Amp) and gets engine temperature information from sensor K120. The ECU varies fan speed dependant on engine temperature and air conditioning (if fitted) pressure.

I believe the ECU continually varies the fan speed, instead of giving just 2 set speeds as in systems equiped with the resistor.
.

 

[Stilo Nutter]

Thanks for the info and pic Davren, what and where is "M10"?

 

[Davren]

M10 is the engine management ECU. On the JTD, it's mounted on a bracket near the coolant expansion bottle.

Pictures below show the cooling fan ECU, and it's location in the back of the fan cowling. One screw to remove the panel and the ECU comes out attached to it.
.

 

[Stilo Nutter]

Ok, thanks for that Davren. I just wanted to know so I could check everything.

I had the Fan ECU out and inspected it not long after you posted the info on the JTD's cooling fan circuit. I also cleaned the earths & checked the fuses for the system.

Mine wont spin at all, I never hear it kick in while driving or when I pull up at my destination and I'm still on tickover and It doesn't activate when I execute it via FES. Makes me feel lucky I have a stuck open thermostat to keep the engine cool lol.

Any suggestions where I should start with given this new info? As always, any help & advice is greatly appreciated.

 

[Davren]

Mine wont spin at all, I never hear it kick in while driving or when I pull up at my destination and I'm still on tickover and It doesn't activate when I execute it via FES. Makes me feel lucky I have a stuck open thermostat to keep the engine cool lol.

I'm actually quite please to hear that. .... Because mine's exactly the same. The only time I've ever seen or heard my fan operating is when I turn the air conditioning on. Then it turns slowly. Mine doesn't switch on with FES either. Despite this, my temperature gauge needle never goes above vertical and the car never overheats, even when I drive to Greece every summer where the temperature is usually 40°C+.

Everything I could test on the cooling fan circuit was OK so I fitted the new ECU in my picture above. It's still the same.

 

[Stilo Nutter]

Thats weird because I'm sure I have got the fan to run via FES. In the early days of just having got both the car and FES I was obviously playing about with both and I have the memory of hearing the rad fan spin from inside while playing with the "activate actuators" section.

Though I have since used FES on a few other fiats and I could easily be mis-remembering, but I would have thought that if I had tried to activate the fan and NOT heard it start up in the early days of having my car and checking for faults, that that would have stuck in my mind more because something wasn't working.

Since me and you appear to be in the same boat, maybe we should ask other JTD owners with FES to try to activate theirs?

 

[Davren]

It doesn't activate when I execute it via FES.

I'm sure I have got the fan to run via FES.

Since me and you appear to be in the same boat, maybe we should ask other JTD owners with FES to try to activate theirs?

Sounds like a plan to me.

I'm not too bothered about mine, it's been like it for 4 years since I've had the car and never overheated, or shown excess temperature on the gauge.

 

[Stilo Nutter]

It doesn't activate when I execute it via FES.

This is how it behaves nowadays.

I'm sure I have got the fan to run via FES. In the early days of just having got both the car and FES

As I said, or at least as I meant to say. I'm sure I have had the fan working via FES before when I first got the car and FES, but this could be a false memory as it was a about a year ago and I have used FES on a few other fiats since.

 

[clock34]

mine comes on with the air con. and can get it running on slow speed on fes but not high speed.

but ive never herd it come on just with the car runing. ALTHOUGH if it indeed just speeds it up as needed you would never hear it slowely spinning anyways so aslong as its not going over half id say its working.

 

[oowop]

I used a long long flat screw driver pushed it into negative side of fan conector and leaned it on engine as to make earth for it. It went full power immediately. So I checked earth from battery to that negative lead and it showed dead fan ECU (on abarth is ECU).

I opened up that ecu and earth goes ok somewhere in the middle of ecu. That repair is beyond me but wouldn't mind some guidance since I have solder and good eye sight.

 

[remis]

Hi. I have fiat stilo 1.2-16v 2002years old. yesterday my cooling fan stop working temperature cam up.any one can help me what i need to check. fuss its ok I all ready check.
kindly Remis.

 

[Davren]

What have you checked from this thread already?