Re-wiring a fan from 3 pin to 4 pin

I know there are adapters and, right now, I'm buying one. But, just out of curiousity, how would I re-wire my current 3 pin connection to a 4 pin?

Just be cool to know... Ya know?

 

Black = Ground
Red = 12v = yellow on power supply
Another color = RPM sensor (doesn't need to be plugged into power supply

the 12v positive will always be in the middle

 

So how do I go about figuring something like this on my own?

 

you can either hardwire the fan to the power supply wires or you can find an existing molex connector to hook up the fan and connect to the power supply.

or the easiest thing you can do is this: http://www.newegg.com/app/ViewProductDesc.asp?description=35-999-104&depa=0

 

If you wanna re-write a molex without a crimping tool, then a pin is probably the easiest way to wiggle the wires out

Personally, I'd get a molex splitter and re-wire the split wires

 

How would a person figure out which wire does what?

Does anyone know of any articles of something explaining this sort of thing?

 

on the fan cable:

Black = Ground
Red = 12v = yellow on power supply
Another color = RPM sensor (doesn't need to be plugged into power supply

the 12v positive will always be in the middle, assuming there's no red

 

Yes... I want to know how you know that though? I want to have some basic understanding of how I could figure something like that out on my own in the future.

Like I want to know what each wire does and how I would figure out which is which...

 

oh ok. yeah, black is always the negative lead or ground as others call it. red will always be a positive lead, although the voltage will never be the same. If you're looking at a 3-pin fan cable, the third wire will always be a rpm sensor and will plug into the motherboard. if you're ever in doubt, you can always use the resistance checker on a multimeter; if there's resistance, a current will go through it and therefore you're playing with both positive and negative leads. as for the power supply, many of those will tell you what each wire does. on 99.9% of power supplies, yellow is +12 and red is +5. you can confirm that with a voltmeter. if you're into electronics or anythign dealing with electricity, a multimeter (such as http://www.radioshack.com/product.a...y_name=CTLG_011_008_002_000&product_id=22-813) will be extremely useful

 

Thanks. I'm not into electronics at all. But, I wouldn't mind learning, it seems quite interesting.

 

yeah it is interesting. i recommend you get a multimeter anyway. it'll help you learn, AND if you want, you can annoy your friends with the continuity tester

 

I wrote a whole guide about soldering and using a mutli-meter and an outline of all the basic functions. However, they were posted on another forum, and I'm not inclined to go looking for the word document right now!

 

Well if you ever find it I'd be interested...