Pc Fan 3 Pin Connector Pinout

This is still considered a 3 pin fan.

Pc fan 3 pin connector pinout. Am putting together a pc and have run into a problem with the mb case. I am building my new pc asus p5b plus motherboard thermalright ultra 120 extreme heatsink and a yate loon fan to cool this heatsink. My mobo has a 4 pin header but my yate loon fan has the 4 pin molex power and a 3 pin connector. Desktop board has a 4 pin fan header.

The older 20 pin main power cable only has one 12 volt line. Three wire and four wire fan connectors. The new 24 pin connector added one line apiece for ground 3 3 5 and 12 volts. Identifying fan type 3 pin or 4 pin pwm.

There is no fan control. A 4 pin pwm fan connector will have four square holes on the front and four wires entering the back. Desktop board has a 3 pin fan header. Some models have the wiring of the white wire speed sensor in the middle whereas the standard 3 pin molex connector requires the white wire as pin 3 thus compatibility issues may exist.

The size and spacing of the pin sockets is identical to a standard three pin female ic connector and three pin molex connector. Fans with three pin connectors must be used on 3 pin cpu fan pinouts. The case fan has a 3 hole connector and all system fan connectors on the mb are 4 pin. There is no fan control.

Fan has a 3 pin power connector. When no revolutions are sensed by the system an audio alarm or no system boot will occur warning the user or preventing proccessor overheating and burnout. When using a 3 pin power connector with a 4 pin fan header the fan will always be on. The 3 pin senses fan rpm revolutions per minute.

Some fans may have a 4 pin connector but only 3 wires going into the back of the connector. A four pin connector is a little different than the three pin connector since it has the extra fourth wire used for controlling and sending signals to the fan which likely has a chip on it that tells it to slow down or speed up in addition to the other wires the three pin connector has. When using a 3 pin power connector with a 4 pin fan header the fan will always be on. Proper fan connector placement is shown in the figures below.

It s been years since i last built a rig so i have a question on connecting the heatsink fan. The 24 pin connector is polarized so it can only be plugged in pointing in the correct direction. The extra pins made the auxiliary power cable unnecessary so most atx12v 2 x power supplies don t have them. Fan has a 4 pin power connector.

Fan has a 3 pin power connector.