Manual steering when wet. ' 99 Ford Windstar Power steering pump, drive belt and belt tensioner all have less than 8000 miles on them?

Manual steering when wet. ' 99 Ford Windstar Power steering pump, drive belt and belt tensioner all have less than 8000 miles on them?

Added (1). it's rainy season here in Florida and when the system gets wet I have to manhandle my steering wheel
What's wrong?

Ok

Check for leaks or rain coming in to the engine compartment. Replace the belt. Adjust the tension.

Check to see if a splash shield is missing under the engine compartment. I'm sure your belt is getting wet.