4 Pin Pwm Fan Wiring Diagram
The four wires.
4 pin pwm fan wiring diagram. Installing the 4 pin trailer wires. Teoretically is possible to use 4 wire fan like 3 wire on the board with 3 wire connector. There is no fan control. Early homemade fan controllers used a simple volt mod by choosing 5 7 or 12v from a classic molex connector.
When using a 3 pin power connector with a 4 pin fan header the fan will always be on. 4 pin pwm header can automatically control the speed of your fans and pumps. Used 4 wire fan for these two projects. The tacho signal from the fan sinks to ground for every revolution the input on the motherboard is pulled high.
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. Fan has a 3 pin power connector. 3 pin fan and 4 pin motherboard connector compatibility. Vice versa it is possible to use old 3 wire fan on new board with 4 wire header but with limited possibility of pwm control depending on board logic.
Update october 13 2008. Fan uses control ic bd6709nfs from rohm company. Usually the diagram is more complicated. Proper fan connector placement is shown in the figures below.
You must check the trailer manual to see if the wiring is correct but normally the white wire is called the ground wire while the brown wire is used for tail lights. The pwm signal from the motherboard sources 5v during the on state of the pulse otherwise it s pulled to ground. Yellow and green are for left and right turns and braking. Start by cutting the white wire and attaching it to the trailer frame.
On these 4 wire computer fans i have found that some times they require an input to tell it how fast to spin so simply supplying power to 2 of the wires will not work if you have a 3 wire fan however you can supply power to the red and black and leave the white disconnected. Sort of explains the pinouts for this kind of fan. Desktop board has a 4 pin fan header. Fans and on board fan headers are backwards compatible.