If you hear a squealing sound from underneath your hood, check the serpentine belt. If it’s frayed or even broken, it’s time to replace it, as this belt controls the alternator, power steering pump, and a whole lot of other important things.
Replacing a serpentine belt is possible to do at home, and frequent DIYers will probably find it fairly easy, but it’s not really beginner level. If you’re more advanced, though, give it a shot.
Grab your owner’s manual and find the diagram of the serpentine belt system for reference, and then pop your hood and find the belt. Then find the tensioner, which should be located very near the belt—check the diagram. Move the tensioner so the belt is loose enough to pull it off.
That’s the easy part. The trickier part is getting it onto all those pulleys. There are a lot of them. Again, reference the diagram in the manual to make sure you’re putting the belt on correctly.
When the belt is on correctly, turn the tensioner back so the belt is tight again and use a belt tension gauge to make sure it’s the right tightness.