4 Pin Fan Cable Explained

This is still considered a 3 pin fan.

4 pin fan cable explained.

Proper fan connector placement is shown in the figures below. The ins and outs of a 4 wire computer fan. Desktop board has a 4 pin fan header. Identifying fan type 3 pin or 4 pin pwm.

Early homemade fan controllers used a simple volt mod by choosing 5 7 or 12v from a classic molex connector. These two extra 12 volt cables two yellow two black give the motherboard the option of accessing more power through these cables. They generally help support the cpu but can be used for other things. A 4 pin pwm fan connector will have four square holes on the front and four wires entering the back.

Used 4 wire fan for these two projects. Some fans may have a 4 pin connector but only 3 wires going into the back of the connector. This version of the power cable is for fans in the case so do not attach it to your hard drive or cd drive. Following is the connector pin out and wire color code of a typical 4 wire fan.

When using a 3 pin power connector with a 4 pin fan header the fan will always be on. A 3 pin fan connector will be smaller in size than the 4 pin pwm fan connector. This power cable can sometimes be found with only two cables. There is no fan control.

It was followed by the use of ordinary resistors to slow the fans down fans equipped with thermal resistors various potentiometers for a wide range. This cable is commonly called the 4 pin molex power cable but this can be confused with the 4 pin main power cable which is a molex cable too. Technically a 4 wire fan is called as 4 wire pulse width modulation pwm controlled fan. Three wire and four wire fan connectors.

The 4 pin power connector cable 12 volt cable is designed to give extra power support to the motherboard. Fan has a 3 pin power connector. Signal description is included as well. 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.