Now you will connect the wires from the fan to any unused peripheral power plug from the power supply. The way you will connect the fan wires to the power supply will depend on the speed you want to configure your fan with. You have three options: low speed (+5 V), medium speed (+7 V) or full speed (+12 V). You may be asking yourself how can we get +7 V since the power supply doesn’t provide such voltage. Here is the trick. If you connect one wire to +12 V and the other wire to +5 V you will have +7 V (12 V – 5 V = 7 V). It works like a charm.
So for low speed you will connect the black wire from the fan to the power supply black wire and the red (or yellow) wire from the fan to the red wire from the power supply. As mentioned this will provide +5 V to the fan. We show how this is done on Figure 10.
click to enlarge Figure 10: Installation for low speed.
For medium speed you will connect the black wire from the fan to the red wire from the power supply, and the red (or yellow) wire from the fan to the yellow wire from the power supply. As mentioned this will provide +7 V to the fan.
click to enlarge Figure 11: Installation for medium speed.
And for full speed you have two options, one is to install the fan wires back to the fan connector or to connect the black wire from the fan to the black wire from the power supply and the red (or yellow) wire from the fan to the yellow wire from the power supply.
click to enlarge Figure 12: Installation for full speed.