I know exactly what the problem is. The outer metal ring is separating from the rubber part of the harmonic balancer(crank pulley). This exact thing happened to me with the same squeaking that got worse when the A/c was started. Also the outer part of the pulley wobbled.
You have a couple of choices. You can replace it with another regular harmonic balancer for $270-$290. Or replace it with a custom billet aluminum crank pulley from Daniel at
3SX.com for $119.00 that was 5 pounds lighter and claims to increase HP by 10-15.
The old one slipped right off and the new one slid on snugly. Once the new pulley was installed, the car was started and the squealing was gone.
The tools I used were a 12mm ratcheting wrench, a 14mm ratcheting wrench, an impact wrench to remove the pulley bolt, and a 22mm socket for the impact wrench. Also a 1/2" drive ratchet was used to fit into the slot of the power steering tensioner to move it.
To access the pulley and the drive belt tensioner you will need to remove the driver's side tire and the plastic panels in the fender well.
Loosen the center 14mm center bolt on the drive belt tensioner then adjust the 12mm bolt you can see sticking up from the top back to move the tensioner.
The power steering belt requires a 14mm wrench to loosen the 2 bolts in the middle and the base. Then use a 1/2" drive ratchet in the notch of the tensioner to move it.
Mechanic skills required on a scale of 1-10 is about a 5 or so.
Set aside about an hour to complete the task.
Rick