My blower motor is making a very high pitched squeal when in the second lowest or third lowest power position. It is very subtle but quite annoying, and it gives me a headache. My car is just off warranty so I'll try to replace it myself. Has anyone done this? I'm looking for some DIY instruction. I've looked at Youtube but they are all older models.

 

Could it be a leaf or foreign material somehow caught up in the fan?

Try checking out the cabin filter. See if it needs replacing, or even do as they don't recommend---play with the fan speeds (leave on MAX HI for a while) with the cabin filter out, and see if the extra volume/air dislodges something that could be stuck and hitting the blades.

 

^^This

My last car had a strange sound at certain blower speeds. Turned out to be the cabin filter wasn't seated correctly.

 

I know I don't have the right car, but I recently replaced the blower motor on my 2003 Toyota Avalon, and it makes a whirring noise on 4 out of the 5 speed settings. It was a "Depo" brand blower motor, so I would advise you not to go with it. If I had it to do over, I would go with OEM on this part. Online the unit is about $125. My local Toyota dealer wants $190, but I would sure try to go OEM if I were you. The weird thing is that after I get going down the road a little bit and pick up speed, the whirring noise goes away, but it is sure irritating at idle speeds and speed #2 seems to be the worst.

On the 2003 Avalon they are not all that hard to replace. I just have to crawl under the dash on the passenger side and try to work upside down. Toyota recommends removing the glove box for easier access which is 5 bolts.