[SOLVED] Will this pwm splitter cable work on my dc fans


The header has 4 pins. Hot, ground, tach, pwm. Those 4 go to 1 fan only, every other split gets 3 wires hot, ground, pwm. The mobo can't read multiple input tach signals, it only requires 1 since all fans are on one header. The hot, ground, pwm is needed by all the fans.

Same goes for DC fans, 3 wires on one fan hot, ground, tach but only 2 wires needed for every other split. Mobo reads the 1 tach input, and only outputs the necessary voltage on the hot, covers all the fans.

If using a pwm splitter, the one fan will get hot-ground-tach with pwm not populated, and the 3wire side is hot-ground-unpopulated-pwm. And the fan doesn't physically connect to the pwm 4th pin, so all the fan sees is hot-ground.

Those fans will only be controllable if the motherboard is set for that header to be DC mode, if it's set for pwm the header sees a constant 12v. If you try and throw a pwm fan into the mix, either it'll struggle with variable DC voltages in DC mode, or it'll be the only fan that works right in pwm mode.



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