Why would your 2003 Rave 4 make a squealing sound when making slow left turns the sharper the turn the louder the sound and it is not the brakes?

The most common would be a loose P/S belt. If it is tight but is still the source, it could be a restriction in the P/S system causing high pressure and resistance in the pump. The most common would be a loose P/S belt. If it is tight but is still the source, it could be a restriction in the P/S system causing high pressure and resistance in the pump.