Hi, my rad fan is constantly on, regardless of temperature. (Turns on as soon as key put in ignition) Its not the air con and obd shows a constant fault. Dash temp display works fine so what are likely causes? Thanks

Relay issue? Used to have that issue on my Fiesta

Sent from my iPhone using Ford OC

Hi, where do I find the relay?

On my fiesta there was a bank of 4 under the bonnet

Sent from my iPhone using Ford OC

Thanks, I found them, I just cannot work out which one it is. Should I hear it switch when the ignition is on if it it working?

I would star by making sure they are all seated correctly. Sometimes removing and reseating.

If I remember there was 2 replays for fan controller.

Also if you get someone to turn ignition on you may hear relay click into action.

Sent from my iPad using Ford OC

I've reseated all relays, no joy. I can hear clickjng but not sure if fan. I cannot work out which relay is fan as where the diagram shows a fan r12, there is no relay!

probably a thermostat issue, if its stuck open then it will force the fan on as the car will think the car is overheating. alternatively if you have A DPF, the car might be stuck in regeneration mode.

No dpf is fitted. I take it's likely to be the coolant thermostat as the dash displays engine temp correctly.

probably so, but I think the dash is the coolant sensor. There are multiple sensors though, the thermostat controls the flow of coolant and triggers the fan, but I think there is another sensor which monitors the actual temperature.

But if the thermostat is stuck open, thats a mechanical issue, so the sensor may still read correctly and is just unable to close, thus sticking open may well leave the fan on.

Can you do the dash trick to see if the DTC is shown? Or get a code reader on it? Should help locate the fault. It sounds as if it's in failsafe mode for one reason or another (usually a duff sensor).

I've cleared the faults and its stopped. Don't know whether it's a temp fix or not.

Fault located. The blue wire which I think goes to purple control switch has rubbed against bodywork causing it to short. Once fixed , all working properly. Happened near to nearside headlight.

Good result!