Dell fan power connections

Today I got two nice 92mm Sensflow fans in the mail (FFC0912DE), apparently they were pulled from some Dell servers. Here's one of them:



When I bought them I was told I would have to rewire the fans, which is fine, I'm good at soldering and all that.

Coming out of the fan there are four cables; yellow, red, black, and green. I assume yellow, red, and black are the usual +12V, +5V, and Ground, and maybe green is a sensor? I've heard about Dell using non-proprietary hardware designs so I just wanted to see if anybody was 100% on these.

The pin connection from the fan is six pin (3x2), with four wires being the ones I already stated, and an additional two wires (blue, orange) going to what looks like an LED mounted on the blue plastic fan shield.

If things are as I guessed, I'm just going to connect the +12V and Ground, and cut off everything but the yellow and black wire.

By the way, this fan states that it runs at 1.5A! Definitely putting a resistor or two in series with this. If 70-Ohm isn't enough and the fan is still loud, I'll probably trying using the +5V (red) cable as my new Ground, creating a +7V difference in the fan.

If nobody knows for sure I'm gonna run +12V through the yellow and black wires tomorrow to see if it works, hopefully I guess correctly and don't kill it lol.

I remember having to rewire a DELL fan from an old server. This sucker had 5 wires: Red, Black, Yellow, Green, Blue.

I only used the universal 3 wires : Red, Yellow, Black. Dunno what the other 2 wires did, but when I wired up the fan to a molex, the dam thing was whailin away @ top speed . My guess is either the green or blue where speed/rpm sensors and would adjust fan speed when needed.

Good luck and hope you don't kill it

Man I had no idea what the heck those cables were.

I connected +12V to yellow and Ground to black, nothing happened. I played around with it and here are the results:

[+] [-] [Result]
[Yellow] [Black] [No]
[Yellow] [Red] [No]
[Red] [Black] [Fast]
[Red] [Yellow] [Slow]
[Black] [Yellow] [No]
[Black] [Red] [No]

So there you have it. Red is Ground. And connecting Black or Yellow to +12V yields different speeds. Also, if both Black and Yellow are connected to +12V, it runs very fast! The power supply I was using could only go up to 0.5A, so I couldn't see that but I'll bet it's pretty loud.

What the hell were the designers thinking?

Anyway I'm pretty disappointed. I ordered these to use in a silent rig but both make an annoying "zzzzzzzzzzz" sound when using a resistor to run at low speeds. =/