1997 Honda Civic Noise coming from blower under glove box

In my 97 Honda i am getting a high pictched whine and rumbling noise from the blower that runs the Heat and AC...it started out high pitched and has now since just become a rumble that is always there unless I switch off the fan and it goes away. Now when I put the switch on one or two it stops and there is nothing....but on three and four it runs.....but still in noisy....planning on dropping the unit....and checking it out...but do not know if it is electirical or just need a new fan.

andy