Hello everyone, I have recently obtained a box of like 30 or so delta fans from a source that shall remain unnamed for now.
Update: Broke a bit of the plastic off the back of one of the fans and found the PCB labels for the wires:
Black - GND
Red - VIN
Yellow - PWM
Blue - O/F
![](http://i.imgur.com/atXZ21r.jpg)
![](http://i.imgur.com/lp8GrsE.jpg)
![](http://i.imgur.com/zBuu9S4.jpg)
The red and black are positive and negative, but the yellow and blue wires have me stumped.
I thought they might be the standard yellow tach and blue PWM wires of a standard PC fan, but they aren't, I terminated them in a 4 pin fan header and the fan ran at full speed. So I thought maybe my dell test motherboard was being... dell, so I just connected the fan to a 12v power supply and touched the blue wire (normally a PWM input) to ground, expecting it to shut down the fan (0% PWM) Nothing changed, still ran at full speed. So I tried the yellow wire (normally a tach wire on most fans) and oddly, it shut the fan down. So I figured maybe delta just switched the tach and PWM colors around, so I did the same, and the fan didn't move at all when connected to my dell testbench. Then I tried voltage controlling it, it was still pretty fast at 7v and wouldn't even move at 5v, so voltage control seems unlikely.
Any ideas? I can't seem to find any datasheets for the 4 pin flavor of this fan, only 2 and 3 pin versions.
Thanks!