How can I keep my fan from staying at full speed after replacing the hard drive? I replaced a hard drive in a 2011 iMac (Core i7), though it was a standard hard drive and didn't have a location for the S.M.A.R.T. cord. (Or at least I think that's what it was.) Since then, the internal fan has constantly been running. I don't want the fan to burn out, and it is becoming quite a distraction for the user.

I believe there is a terminal command that turns off the fan, I believe by bypassing the S.M.A.R.T. test, but the Google gods are not forthcoming with this information. Does anybody know how I can turn off the fan?
Macs Fan Control can set the fan of an iMac (or MacBook, or other hardware) to any speed. The coolest thing that it can also set a fan to sensor-based control depending on your new HDD by reading its S.M.A.R.T. temperature. 

This free app is much better and powerful than HDD Fan Control, which is currently deprecated but still costs $35. Macs Fan Control also works under Windows in Boot Camp.