Problem: external power supply for fan

[Jon8RFC]

I put my brother-in-law in a difficult situation. I had him buy the following two products:
http://www.newegg.com/Product/Product.aspx?Item=N82E16835209005
http://knightdiscounts.com/estore/4pin-molex-external-power-supply-p-1886.html

I didn't read the description (PEBKAC, I know...I was hunting for the least expensive supply, plus shipping/tax) and he said the fan will not spin up as a result of pin 2. All this will be used for is powering that fan to cool the rack of an entertainment center--it will never power anything else like a hard drive. Can I simply swap pins 2 and 3 on a short molex extension and send that to him to use as an inline adapter? Pin 3 has to be grounded for a hard drive to work (right?) so I can just swap them for a fan-only use, correct?

 

[BillR]

pin 1 should be 12+ (Yellow)

pin #2 should be ground (black)

pin #3 should be ground (black)

pin #4 should be 5+ (red)

Normaly 2 and 3 share a common ground. Your PSU states #2 is ungrounded, so, no 12v for the fan.

You could move the #2 wire on the fan plug to #3 for your ground, or you could jumper #2 and #3 on the fan Molex to obtain your needed ground..

Not being able to see inside the PSU please double check with a mulit meter before you make changes. As it stands you should see NO continuity between 2 and 3 on your PSU which should confirm your #2 is not grounded.

http://www.helpwithpcs.com/courses/power-supply-basics-inc-pinouts.htm

A little care, pin numbering between companies is not always equal.

 

[Jon8RFC]

Thanks, Bill. I don't have access to it (he and I are in different states), but your thoughts on jumpering #2 to #3 are what I had.

Yeah, I'll take into account the chance of a different vendor using their own standards, but the principle theory is what I'm targeting. =]