Thermo fan - what switches it on?

[MinniTheMoocha]

Hi all,

Just wondering if the thermo fan on a defender '98 300tdi only comes on if the A/C is switched on?

Does water temp at all switch it on?

Thanks

MtM

[Blknight.aus]

AC only

although I do know of people who have hooked up an override switch so they can turn it on manually or via a thermal switch in the engine bay

[MinniTheMoocha]

AC only

although I do know of people who have hooked up an override switch so they can turn it on manually or via a thermal switch in the engine bay

I thought that might have been the case. My thermo fan is slightly seized!

My car was reaching 100 Degrees on some hill climbs both when on the road and when in the bush. It didn't get hotter than that and the head temp did not get above 85 Degrees C. Thought maybe the thermo fan would come on when a certain temp is reached.

Really looks like getting the radiator rodded or a new one will be the fix for my temp getting to 100 Degrees C.

Should it ever get this high? 100 Degrees is not above the limits of a 15PSI system.

[Blknight.aus]

nope 100 is fine if youve driven the same track in the same condition of load, road,temp and tyres before and it didnt get that hot then its trying to tell you something.

If it was hitting 100 on a normal day with a gentle highway cruise ID be more worried.

[scott oz]

My understanding on the air con models the thermal fan is activated either by the air cond being activated OR when the engine temp reaches a predetermined level the ECU activates the air con fan

[justinc]

...For a Td5 yes, a Tdi is stand alone A/C only.

JC