Hi Billy,
There are two blower fans one each side under the dash,so first you need to find which one is making the noise.
Could just be some debris in the blower compartment,try putting on full and leaving for 15 to 30 seconds to see if it makes a difference or anything comes out of the vents.Sometimes leaves or the foam insulation can get trapped in there.
Here's what your looking for:

- Blower Assembly
1 Heater blower
2 Servo motor
3 Power transistor
4 Harness
5 Nut and washer
6 Plain washer
7 Setscrew
8 Blower motor fan
9 Heater blower
Detailed info on removal can be found on pages 1778-1781 in the X308 Workshop Manual,if you don't have one P.M. me your email and I'll gladly send you one in PDF.
Hope this helps,
Good Luck with it anyway.
Andy
