Why is my car making a squealing noise when the AC is turned on?

When your car makes a squealing noise after turning on the AC, it’s usually due to belt-related components. The most common causes are a worn or loose serpentine belt, a weak belt tensioner, or an idler pulley starting to fail. Turning on the AC puts extra load on the engine, and worn parts can slip and make that squealing sound.

If the noise keeps happening, it’s best to get it checked before the belt fails completely. My best shop is Bergman’s Auto Repair they inspect the belt system and AC compressor to determine whether it’s a simple belt replacement or a part that needs attention.