I think I have an issue with my thermo fan, so before taking it anywhere I want to get some ideas,

Now what happens is within 30 seconds of starting the car the thermo fan cuts in at full tilt.

The car is a BFMKII ghia with 70k on the clock. so it only has a single fan. the climate control clicks the air con on and off to keep the condenser at temp being set to auto which is normal.

I have checked things like coolant and that the radiator is clean, the engine doesn't seem hot and the temp gauge looks normal.

before anyone says they are noisey, even on cold morning like 15c before I have even backed out the driveway the fan has cut in on high and can be heard over the engine even in the house.
I have even stood out side while the car has been driven past at 50kmh and the fan is heard before the actual car. even though the day was only 20c, when travelling at 100km/h it makes a vibration sound, i guess being speed up by the airflow. even in warm weather the fan never used to be that loud.

anyone have any ideas what it could be.

while writing this I thought i should check the fuses.


Cheers for any rsponses

ok so I rang our ford dealer and he is closed for another 2 weeks (country living).

I have been playing around with the car, now if I turn the air con off the thermo fan doesn't come on at all and the temp gauge goes up to half (where I have never seen it get to).

its like the the computer isn't being told the engine temp and the condenser for the air con is getting to warm and over riding the computer thinking that the fan speed ins't high enough and upping it.

now I'm pretty sure the temp gauge on the dash come from a different sensor that the fan uses.

any have a manual that says which sender the fan works from, I was thinking if I could swap the fan sensor and the sensor that talks to the dash to test.

Trying to get this sorted before we travel.

Cheers

well even know no one had any suggestions, I found someone who had a scan tool and it came up with a fault codes that said there was a fault with relays or wiring to the fan.

which happens to be right. I put a multi meter on the pins to the fan and the air con low speed voltage is only giving out 2.3 volts, then high speed is 13 volts.

now the thing is I know with dual fan set-ups to get low speed the fans are wired to receive 6volts each, but how does the single fan get 6 volts.

well I think I have found the problem on a single fan system there is a voltage reducer well that's what I think it is mine is all cracked and has burnt marks.

its located behind the wiring plug on the shroud and is cooled by the fan.

For future reference this device is a thermistor and changes fan speed according to air temp coming through the radiator, so low fan speed is variable and high fan speed is fixed, which is full tilt.

Sorry no one replied mate but good on ya for updating the post and with pics as well, no doubt this will help someone in the future

Cheer
Phil

yeah well I rang 4 parts places and one of them said they have replaced one of these, there was one left in Australia. pretty much ya just have to change the while fan assembly, found after market fan assembly's for just under $200.

Yeah Phil I thought it would write this up as I would assume over the years to come others will get the same problem as my searched came up with nothing.

So its now buy the whole fan and shroud assembly to get the resistor that controls the fan speed.

The only place ive found them is on Ebay Aust,
"BF Falcon Radiator Fan Speed Resistor",
@ $140, which is a true rip off.

$144.50 & up


also postage.......