1.9 tdi Both fans on

[Cosmos]

Hi, Wondering if anyone has any ideas to whats recently started happening to the wifes mk5 1.9 tdi with 75k on the clock.

When you start the car after about 10 seconds both fans on the radiator come on. You can turn the engine off and on again and they dont come back on but sometimes after a drive they have went on at some point as when you turn the engine off you can hear them spinning down as they are quite loud when they are on. The problem doesnt seem to happen every time and quite intermittent but its a right pain.

Have bought and swapped over the coolant sensor and plugged the car into a pals snap on device with no faults showing. Have had a look for the fan relay but theres nothing with the rest of the relays above the accelerator pedal and under the bonnet that i can see as had the airbox off and had a good look down at the fan connections etc and see no relay there.
Am stuck now what to do before i have to take it to a garage.
Any help would be great 🙂
Thanks

[Cosmos]

Have unplugged the air con pressure switch and tucked the cable up out the way and the fans havent come on once after numerous start ups.Hoping it is something like this switch.

[maxamplitude10]

Usually a temp switch issue, ECU doesnt know temp so defaults to fans on? This is what is was on my gti anyway

[Cosmos]

Thanks maxamitude10.

Was booked in at a vw specialist garage yesterday and got the switch on the aircon ( down by the aux belt ) replaced and also regassed.Seems to have cured the problem as they havent been on since.

[maxamplitude10]