Not sure I can help, but what is the SPAL part number of the fan which you have? I'm curious to read the installation manual for it...

There wasn't much information out there for the SPAL brushless fans a while back. If I remember right, the PWM controller is already built into those fans and are designed to run off of their sending unit.

Spal 30107035 (VA97-ABL309-98A) 17" brushless fan.

I've tried to look for any information on it, but cannot find very much. I was able to find a few schematics using their temperature sending unit and have the factory schematics, but I'm hoping to be able to use the ECU to control it.

I thought about running it in analog mode using the factory PWM controller, but don't know if that will function as originally designed.

http://imagizer.imageshack.us/v2/160...673/ouX47j.jpg

http://imagizer.imageshack.us/v2/160...907/K0QmdL.jpg

This is the only info I could find on that specific fan.

http://imagizer.imageshack.us/v2/160...903/uahsBn.jpg

In the above circuit diagram, what does this symbol represent:

http://i242.photobucket.com/albums/f...itt/symbol.jpg

Male/Female Inline Harness Connector

Ah, thanks. I didnt know if it was some type of electrical component. First thought was maybe a Diode, but then remembered it was a triangle with a line.

It seems that Spal makes various components to make this fan operate in PWM mode without using any sort of ECU, is that right?

Andrew

Yes, they make a temperature sensor which controls the fan, but I still want to be able to control it using my ECU and tune.

I had a decent email conversation with SPAL tech support today. He informed me that there are only three wires going to the fan pos/neg/pwm. The yellow analog/override wire shown in the one schematic isn't actually present on the fan and that I need to use their white pwm wire to tell the fan how fast to run.

I told him I had the ability to adjust the pwm frequency and duty cycle in my ECU and he provided me with this response curve, but I still don't know how to make it work.

http://imageshack.com/a/img909/7557/1fPP9r.jpg


So now the question is what how do I use their pwm wire with my ECU.

He said 128 Hz should be ok, but if I really want to change it 100Hz would be the optimal.

Can I just change my PWM frequency in my ECU to 100 Hz and connect the green pwm fan controller wire to the white pwm fan wire?

What ECU are you using?

Andrew