Motherboard (CPU) 4 Pin Fan Connector Pinout - AllPinouts
From AllPinouts
4-Wire Pulse Width Modulation (PWM) Controlled Fans

Motherboard CPU Fan 4 Pin header Connector.
| Pin | Name | Color |
|---|---|---|
| 1 | GND | black |
| 2 | +12VDC | yellow |
| 3 | Sense | green |
| 4 | Control | blue |
For some AMD cpu fans:
| Pin | Name | Color |
|---|---|---|
| 1 | GND | black |
| 2 | +12VDC | red |
| 3 | Sense | yellow |
| 4 | Control | blue |
Notes
- Colors may change.
- Chassis and CPU fans may use either 3-pin or 4-pin power connectors. 3-pin connectors are usually used for the smaller chassis fans with lower power consumption. 4-pin connectors are usually used by CPU fans with higher power consumption. Fans and on-board fan headers are backwards compatible. Proper fan connector placement is shown in the figures below:

