My AF 566 whistling billbaord sounds like a vacuum cleaner. Any ideas as to what is wrong?

Hi Sy, welcome to the Forum!
Now, do you mean that the motor is loud, or is it that there is no whistle?

John

I think I know what you are talking about. I cleaned the motor and the whistle air area, and it sounded a lot better.

The sound chamber or impeller needs to be serviced. You'll need to remove the motor and whistle housing from the billboard. Careful to note where things go and save the spacers. Once you have the unit out, disassemble the motor, and clean all the parts. The armature should have an impeller pressed on to the other end. If you can pull the armature out and the impeller falls off or spins on the shaft, then you need to replace the impeller as its become loose on the shaft. If this is fine then look at the whistle chamber cover. If yours happens to have screws, tighten them. If your unit has push pins, and most do, then your going to need to use a vise and gently press them home again one at a time. Be very careful not to crack the cast part of the housing. An alternative method would be to use daubs of silicone sealent, and rub it in along the edge of the cover in an attempt to seal the gap where the gasket has shrunk. Leave that dry for a day then test.

PRRDave