Recently, my fan blower has been making a strange squealing or loud whistling noise on startup. The AC is on (we are in summer) the car starts and this loud squeal starts. During this time no air is being blown out. After ten or fifteen seconds the squeal stops and the fan starts to blow air though the vents.
It s a sound that is almost as if it is trying to blow air through a closed internal valve or vent?

Increasing the fan speed control up and down sometimes seems to fix it sooner.

Once it is running the system works perfectly and without further issues, until the next morning.

Any suggestions? ...maybe a vent relay?

The fan control resistor / mosfet was replaced recently and I do not suspect it.

Many thanks!

Phil

 

Your fan motor is probably rusty. Is the floor mat on the PAX side wet towards the center? Your AC condensate drain may be plugged. "duckbill"

 

Yes, most of us with older cars have been through this.
The bearings are worn. You can mess with it and add grease... and that will give you a couple of months. (experience)
OR, replace the motor/fan assembly.

 

Easy to dismantle (and remove) - mine was squeaking from what looked like carbon dust from the brushes, cleaned it out, oiled the bearing as best as I could - been fine for at least 6 years. Be careful removing the cover as the funny clips are easy to destroy:

 

Excellent! Thanks all.

My instinct would be the fan motor / bearings.

Ah the dreaded duckbill issue! - I have no condensate (phew!) so I am not suspecting that little nugget!

Although at some time I am sure that I will be negotiating the supercharger to snake behind and drill that sucker out ;-)

I will post my results to help with any future owners, probably after the weekend.

Cheers!

Phil