Loud noise/vibration when using heater or air conditioner on 1998 Oldsmobile Intrigue

When I use either the air conditioner or heater I get a very loud vibration/noise. It still heats or cools, but so loud it can be heard outside of the car. What is this? I tend not to use it except for a minute or two at a time, then turn it off. This happens EVERYtime I use either and starts within 15 seconds of turning them on.

3 answers 2 comments
Blower motor bearing worn, debris in blower wheel. Remove fan unit clean or replace.
Thank you...i'll start there.
blower motor bushings or fan blades are bad
Thanks for taking the time to answer, i'll check it out.
ac compressor