TechWareLabs has published a guide called "Apr 2nd 2007 How to Hot Wire a Power Supply for Accessory Testing"

Do you need to test your accessories but your worried what that water cooling system or TEC cooler may do once inside your case? Test it outside your case in 5 simple steps using our guide an a spare power supply and save yourself and your system needless problems by checking out that accessory first.

Test your Accessories and Hot Wire a PSU in 5 Steps