Radiator fan not working when it should

[Peter Lobo]

Hi all

Wondering if anyone could shed a bit of light on my overheating 2010 1.25 petrol fiesta.

The radiator fan does not come on when the engine gets to temperature , i have changed the thermostat, changed the coolant temperature sensor , changed the relay , changed the fuse, and still the radiator fan will not come on.

i can operate the fan using the diagnostic scanner and also control it by removing the relay and adding a shorting link , other than this i am completely baffled as to why it will not come on when required .Someone mentioned the BCM but as i can control the fan with the scanner im not so sure.

Any help would be greatly appreciated.

[isetta]

You say ‘when the engine gets to temperature ‘ what do you mean by that. If the engine is getting to overheating temperature without the fan coming on I might be tempted to control the fan by a switch on the dash which you switch on and off as neccessary .  Not ideal but if it means you can use the car it’s better than having an overheating car. Sometimes when you can’t fix it you have to improvise. I know some people will say it’s a bodge. 

[unofix]

22 minutes ago, isetta said:

I know some people will say it’s a bodge.

It's a bodge !! 🤣

[unofix]

21 hours ago, Peter Lobo said:

The radiator fan does not come on when the engine gets to temperature

The fan is not superposed to come on when the engine gets to temperature. It is only meant to operate when the coolant gets above 106C (if I remember correctly). The normal operating temp is between 90 and 100C so mostly the fan is not required.

[Peter Lobo]

Hi All problem solved

 

the thermostat is designed to open at 88 degrees and the fan does not turn on until the temperature of the coolant reaches 106 Degress , i was expecting it to come on at 88 Degrees , my mistake but thanks to the people who read the topic and to the guys who took the time to reply. great forum by the way.

[StephenFord]

30 minutes ago, Peter Lobo said:

Hi All problem solved

 

Gosh, @unofixwas correct, who'd ever have thought LOL