[JDanno]

I'm hooking up two computer cooling fans to provide defrost air for the windscreen. It has three wires. Two are obvious but what is the third wire (yellow I think) for?? Thanks, Dan

 

[roee]

I'm hooking up two computer cooling fans to provide defrost air for the windscreen. It has three wires. Two are obvious but what is the third wire (yellow I think) for?? Thanks, Dan

The third wire is used for sensing fan speed. You can leave it unconnected.

 

[Kahuna]

Yellow is speed sensor that goes to the motherboard if memory serves me. You can disregard it.

 

[JDanno]

Thanks!!!!

 

[noelf]

On a DC powered fan...

...the third wire is used as a tach feed back to the fan controller to validate fan rotation.

On a PWM fan, you get fan power, fan gnd, and the third is pulse width modulation that defines the fan speed and also the feedback signal. This type of fan requires a dedicated fan controller chip or logic.

 

[9GT]

A timely post,,,,,,I just spent today installing my defroster fans in my -10. I am using one for each vent and also one for cooling the radio stack. These are light and the price is great: http://www.surpluscenter.com/item.asp?item=16-1358&catname=electric

 

[SteinAir]

Snip it off and don't look back!