AC Assembly Failure
The 2005 Sentra I bought [got ripped off by] from AutoFlex has only 62.6K miles on it. Recently it started blowing hot air - - - regardless of what setting was selected, ac on or off, all the way to heat, all the way to cool.
Come to find out this apparently is a MAJOR problem with this vehicle, and possibly for other model years. My local shop tried to find it used and failed, after searching the NATION!!! Nissan only sells the ENTIRE AC/HEAT ASSEMBLY from the dash panel forward. $423 from Nissan - - - and then you add on the labor, etc.
Good luck if you own one and have not had this happen yet. Dump it now, before you get burned like I did.