Thermofan Thermostat - what doesn't work...

[MightyMouse]

Ok - so my electromechanical Thermofan thermostat died, the capillary tube fractured at the bulb leaving me to fish it out of the top hose

So what about an electronic one, with some decent adjustment for set point and differential ? Easy.

But I didn't want to add another sensor so why not tap into the EFI block sensor ? To cut a long story short its not really practical.

Issues :

The signal is around 400mV at operating temp with only a few mV change over the temperature area of interest - so getting a small differential was proving very difficult.

And the big one - the reference voltage applied to the sensor is not stable enough - it fluctuates by a few tens of mV with changes in battery / alternator voltage causing unpredictable cut in and out.

So don't waste you time - just add a separate sensor.

For the tech minded the EFI system really only uses the block temp sensor for cold start and warmup - once its up to temp its pretty well ignored which explains the low sensitivity at operating temp.

The temp gauge sensor is also no good as the system works on a different principle.

[murcod]

Spend $35 at your local auto parts store and buy a Tridon thermal switch. That's all I did with mine- I heard too many bad reports on those adjustable ones that get shoved into the radiator hose.

Just mount it into the metal coolant tube that runs across the top of the exhaust manifold.

[MightyMouse]

Nah - too easy.....

besides I have two fans, staged and PWM controlled - uses an ATMEL micro running PID and a couple of 100A power switching IC's - virtually indestructible.

Haven't you ever wanted to hook a laptop up to your thermofan controller and have a little chat ?

[dai-hard]

There a guy in sydney who repairs capillary tubes.

I take all our works gauges (compessors/gensets etc) to him they have ethor in them not cheap about $100 to repace the bulb last time i got 1 fixed.

Bit of a hi-jack but thought MIGHTYMOUSE might know ferozas run a speed senor and electronic speedo. Im gettin a late model feroza cluster and was goin to get the tacho convert to 6cyl and run the speed senor(marks) im using for my ecu (std ac delco) to run the feroza cluster.

cheers Craig

[MightyMouse]

Thanks dai-hard but have the electronic one just about done...

My F300 runs a mechanical speedo but the auto also has a VSS used for the converter lock.

I'm not quite sure if your asking does it or can it........

[dai-hard]

Really just wasnt sure whether ferozas were cable or elec.
If there cable ive got no worries.
If there electric i was wondering if the VSS im using for the v6 converion from MARKS ADAPTORS would run the speedo.