au falcon correct thermo fan operation

Maka · 20-03-2010, 08:53 PM

G'day guys,this is my first post so please be gentle! You guys have saved me some good dosh with all the info i have gleened off this wonderful forum-thanks heaps to all you falcon enthusiusts.To my problem, can fellow au l6 owners or experts please let me know how my thermo fans should be operating? My thermo fans have now decided to now come on low speed when the temp needle gets to the first line near the n of normal and seem to switch off when driving above 20 kmh, also with engine cold if i put the a/c on high settings the fans come on low speed and if i switch off a/c while engine cold the fans still run. If i pull the connector off the temp sensor on the back of the head the high speed operation works correctly. The temp needle sits around n or o when warmed up but when i pull up to stop the fans keep coming on? Is this normal? Im pretty sure the fans used to come on only when required. i have researched my problem for a while now and some people say its normal and other people say its not. My au falcon futura s1 is stock as a rock but recently had a reco transmission, new alloy radiator and thermostat installed. The coolant is also new, levels are fine and its just had a oil and filter change, also new plugs , leads and inlet gasket. I do know my battery is on its way out and there is a slight miss at idle- ive checked my coilpack with a multi meter and secondary resistance was fine but primary resistance was 1.2ohms - the manual says turf coilpack if resistance is above 1ohm (coilpack will be replaced next week) . If some one could shed light on this problem it would be very much appreciated as i would like to end this frustrating little saga asap- i love my falc, it drives so much better than my missus's vt bombadoor i cant understand why the motoring media of the day gave it a bit of a suss reputation . Thanks to all who take time to have a read of my post, cheers Maka

**Mechan1k** · 21-03-2010, 02:15 PM

Sounds like normal operation to me ... your fans will be on most of the time with normal operation ... they will spike to the high speed when A/C fan speed is up near maximum ... and when stationary in traffic and the needle is around the right side of the O.

I remember seeing a table with the specified temps for when high/low speed fans kick in .... but for the life of me at the moment can't find it.

Maka · 21-03-2010, 06:47 PM

G'day guys,thanks for the prompt reply Mechan1k much appreciated. I do know you've uprated the cooling system on your au ute and you definately know what your talking about! Ever since ive owned the falcon its basically done short stop start trips not having much chance to warm up but its been doing more kays now and getting up to operating temp. Over the last week ive looked at the relays and swapped them around and they seem to be fine, also i have been keeping an eye on the cooling system and its not overheating or losing coolant (from what i can see) and the temp guage seems to be reading correctly. I always thought the ecu reads the temp sent by the sensor on the back of the head and operates the fans when needed and shuts them off when the engine is at optimum temp. My fans are always on they never shut down. I'll try and get the dash into diagnostics mode and see if the operating temp is consistent with the dash temp guage. If it is normal i'll just monitor the situation & see how it goes . If there are any more issues with my cooling system i'll keep you posted. Thanks once again Mechan1k , Cheers Maka

**Mechan1k** · 21-03-2010, 07:00 PM

I actually traded the ute a couple of years ago now ... i think it was that long ago.

But I did have issues with the cooling system in mine.

You will find when at normal running temperature you should be seeing 91-92 deg C in the dash diagnostic mode.