I've been attempting to get this 4-pin brushless dc pc fan working for some time now. It has a red (+) black (-) blue (PWM in) and yellow (tachometer out).

I only want this fan running at maximum speed and I have seen people run these, like in this video without the PWM blue wire. However, they are still using the tachometer output, which I think it unrelated... I still cannot get it working.

I think I've tried any combination of wires connected to either + or ground.

Any ideas?

  • \$\begingroup\$ What voltages are you using? It is quite possible the power is drawn from 12V, and the control PWM signal is at 3.3V or 5V. If you have applied the 12V at the control wire it is quite possible you have damaged the fan's control circuitry. \$\endgroup\$ – A.S. Nov 7 '18 at 8:10

Connect +12V to red and 0V to black leave the other wires unconnected. If that doesn't work the fan is busted.

This is based on the assumption that this similar to the AFB series fans. (and every other common 12V tacho/pwm fan), I could't locate the AFC series on the Delta electronics web-site.

some of their other fans have blue as tachometer out and yellow as pwm in.

| improve this answer | |
  • \$\begingroup\$ Yeah doing that results in a short jolt and nothing much else. I would try spinning it but I don't want to push reverse polarity into my switch mode psu. Is a switchmode psu good for this? \$\endgroup\$ – Oleenick Nov 7 '18 at 8:15
  • \$\begingroup\$ I'd guess that you burnt out the mosfet that switches magnetic field while you were experimenting, eg: connecting blue to +12 would do that. \$\endgroup\$ – Jasen Nov 7 '18 at 8:18
  • \$\begingroup\$ Yeah that could have happened, but I'm pretty sure I tried only red and black first. I suspect that it may have also been broken before I used it \$\endgroup\$ – Oleenick Nov 7 '18 at 8:22

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.