Noisy blower, Deville '97, 110K

For some reason this summer the blower became noisy. When AC is on, it sounds similar to airplane ready for take off, maybe just not as loud. I don't know, AC works and blows all well but the air flow now makes this somewhat deep additional noise, I was even thinking something got stuck inside and might not allow air in/out but it blows well!

Any advice?

Sounds like it is time for a replacement! If you do replace it yourself, be sure to keep the spark plug wires routed away from the blower motor, as that can cause premature failure.

Can you tell me where it is located?

THe blower motor is on firewall in the engine compartment, right between the back of the engine, it should be relatively easy to remove and replace.