depending on how low it is, it is either the fan rubbing against the casing or the belt that turns the fan coming loose.
The squealing noise from your car's AC when you turn it on could be due to a worn-out or loose drive belt, which may need to be replaced or adjusted by a mechanic.
The squealing noise in your car when the AC is turned on could be due to a worn-out or loose drive belt. The belt may be slipping or not properly tensioned, causing the noise. It is recommended to have a mechanic inspect and possibly replace the drive belt to resolve the issue.
Your air conditioner may be making a loud squealing noise because the AC compressor, which helps cool the air, could be malfunctioning. This could be causing the noise you are hearing.
check a/c compressor and belt.
If your AC unit is making a squealing noise, it could be a sign of a belt issue or a problem with the fan motor. It is important to turn off the AC unit and contact a professional HVAC technician to inspect and repair the issue to prevent further damage.
Loose or glazed fan belt?
check your belts they can be worn and need to be replaced or they just might be cold unless its everytime you start the car if that's the case the might need to be tightened your ac belt or fan belt could be bad.
Loose or worn belt(s).
Check for a slipping drive belt between encine crank pulley and AC compressor pulley.
More likely the bearings in your alternator wearing out. Get a new alternator.
You may need to adjust your belts, check the ac belt first.
you should check the belts. Sounds like one is a little loose and slipping. or the system may be over-charged