Just checking
Thank you. Through this conversation, I have discovered that shorting the PWM signal wire to ground causes the blower to run full blast on the HCH2 fan (different but similar). My previous attempts failed because I used a ~25W power supply, and it would just pulse gently. I hooked it up this evening to a 1000W supply, and it created gale force winds. When I put in a HF multimeter in 10A mode, it tripped off at 4A and started pulsing.
Can you recall the mapping of the connector? I suspect that by shorting those two together, you fed back to the tach ground vs. the negative power lead through the fan controller. I suggest you short the blue PWM signal wire to the 12V ground of your power supply. The tach cable is yellow.
I also tried with a 6A 12V PS, and that almost did it. Guessing it needs about 10A.
All of the above was done with a spare fan outside the car.
Steve