But it only does it when I turn the wheel. What would change when turning the wheel that would only make it squeal when doing so? Any troubleshooting advice?

 

Check the belt tensioner ! Mine did it after a new belt but the tensioner wasn't working right so i took the belt off and sprayed pb blaster in it and worked it back and forth and now its good !

 

Also, check to ensure that the power steering fluid level isn't low.

 

Your making the power steering pump work harder when you turn the wheel. Check if anything is leaking and getting on the belt and pulleys. You may just need a new belt. The tensioner pulley may be sticking and not tightening the belt. Also check the idler pulley to see if it spins smoothly or feels rough indicating the bearing is failing.

 

Ditto on checking the tensioner. And also the power steering fluid. If you turn the wheel, the pump works harder, which makes for more resistance at the pump pulley. If the tensioner isn't working right, then when you turn the shell, the belt slips on the pump when resistance is created.