OK here are some pics (these are the 7-12 Volt pics)
On this last pic, the left side molex is from your power supply, and the right side is going to your fan.
Go down to Radio Smack and buy a 3 pole switch. Mine had poles for two seperate circuits so you could create two circuits from the one switch, say on circuit to switch from 5 to 7 volts and then the more common one of 7 to 12 volts.
7-12 Volt Switch:
Basically when you make a 7-12 volt switch, you want the yellow or hot lead to be common between both circuits (think of the yellow 12V as your hot lead). The yellow lead will not be attached to the switch, it passes right through to the output connector where the yellow lead would normally be. You then solder your red and black leads to either end pole of the switch (think of the red and black as your ground........either 5 or 0 volts).
You'll then solder a black lead from the center pole of the switch to the ground lug of your molex connector.
5-7 Volt Switch
Basically when you make a 5-7 volt switch, you want the black lead to be common to both circuits, so we're doing the reverse of the above, and now your ground is common, not your hot lead. Your black lead will pass through and your red and yellow wires will be soldered to each end of the switch.
You'll then solder a yellow lead from the center pole of the switch to the yellow lug of your molex connector.
Sorry, I forgot to take pics before I hot glued the connections so they wouldn't short out. Hopefully this helps.
