Wiring computer fans

[popeyemth]

Adding a couple fans to the exhaust stack on the fridge .
One has two wires, a black and a red so that's simple.
The other one has three wires, with one showing a short black tracer in the insulation. Would that be the negative lead with the other two hooked to positive?
Thanks in advance to the brain trust here. 🙂

Moderator edit to re-size picture to forum limit of 640px maximum width.

[popeyemth]

Ding Ding Ding we have a winner !!!
The wire with marked insulation was the ground wire just as shown in the pic from 3.0Charlie.
Thanks again,
Mike

[Nick-B]

Yup. The third wire is the RPM feedback to the motherboard.
Not needed for your application.

[3_0charlie]

This is the R4 from Coolermaster. Typical computer fan with +/- leads, and the RPM tach.
Good high-CFM fan, while quite noisy.

[Artum_Snowbird]

do a google search for computer fan wiring. I had a look, and there are images and explanations there.

[Lynnmor]

May be an output to report the RPM to the computer.