Originally posted by Mrfreddio55
Hmm okay thanks for all the help guys... ill post back when i get some info on the particular fan ill be using to make sure i have the correct POT picked out
If you cant find the starting voltage specs for your fan, you can do trial and error at 5V and 7V.

For 5V -
connect the fan leads to a molex connector from your PSU (fan positive to molex red wire, fan negative to molex black) and see if it starts.

For 7V -
Fan positive to molex yellow, fan negative to molex red) and see if it starts.

Whichever one it starts at, use that as your 'starting voltage'.
Most fans have starting voltage of about 6-7 V. Some may start lower than that.