Electric fans constantly on.......help needed

Hi Guys, got a 2002 Disco TD5. Recently over-heated when bottom hose split. Have fixed the problem, however, my electric cooling fans are now constantly on and won't turn off.

I have checked the fuses and relay...all good. I have replaced the engine temp sensor and still the fans are on. The disco has air con and that works as it should. Land Rover have suggested i change the ambient temperature sensor next or pay £88 for them to do a diagnostics test. Can't really afford to do both.

Has anyone experienced the same thing.......advice gratefully appreciated.

Thanks....

GreyCat said:

Hi Guys, got a 2002 Disco TD5. Recently over-heated when bottom hose split. Have fixed the problem, however, my electric cooling fans are now constantly on and won't turn off.

I have checked the fuses and relay...all good. I have replaced the engine temp sensor and still the fans are on. The disco has air con and that works as it should. Land Rover have suggested i change the ambient temperature sensor next or pay £88 for them to do a diagnostics test. Can't really afford to do both.

Has anyone experienced the same thing.......advice gratefully appreciated.

Thanks....

Click to expand...

I'm assuming you mean the electric fan in front of the radiator? I had exactly the same thing and resolved it, after buying a new temp sensor.

You need to get hold of a HawkEye or similar diagnostic tool. Under the TD5 EMS menu, you will find a setting for A/c fan assist - this will show Yes or On. Change this to Off or No and your fan will stop being on all the time.

Once you have done this, to check for correct operation simply start the car WITHOUT aircon being selected and the electric fan should be dormant, then while the engine is ticking over, select aircon and the fan will start.

This was one of the first jobs I did when I bought my HawkEye.

Cheers
Dave

GreyCat said:

Hi Guys, got a 2002 Disco TD5. Recently over-heated when bottom hose split. Have fixed the problem, however, my electric cooling fans are now constantly on and won't turn off.

I have checked the fuses and relay...all good. I have replaced the engine temp sensor and still the fans are on. The disco has air con and that works as it should. Land Rover have suggested i change the ambient temperature sensor next or pay £88 for them to do a diagnostics test. Can't really afford to do both.

Has anyone experienced the same thing.......advice gratefully appreciated.

Thanks....

Click to expand...

Hi, if u are familiar with electric diagrams I can give u some tips where to check some feeds........first of all u have to know if the cooling fan request which is activating it is comming from the engine management or from the air conditioning system.

Run a manual test on aircon system and if the AAT sensor is gone u'll see........if not then the ECM must be reseted and u have to plug it in a tester........can't u find a hepfull chap with nanocom or hawkeye near u to get help?......88 quid to a diagnostic is huge(pure robbery).if u dont have RAVE see this...if u get code 12 then replace the sensor