Power steering issues

My 07 Nissan Maxima has an odd power steering issue. What it does is that when it is a warm dry day the power steering sticks like it doesn’t have power steering at all when it first starts but when I turn it on and get the car moving it works fine; however on a wet day when it’s raining cats and dogs it works as if it never had any issues at all

Has anyone tried replacing the serpentine belt?

Tester

Check the fluid level in the PS system too.

It looks ok.

You can’t tell whether or not a belt is worn just by looking at it.

Tester

I took off the belt and it’s fine. The power steering fluid looks thin and watered down.

Replacing the power steering fluid makes sense. Shouldn’t be overly expensive. The entire power steering hydraulic system should be checked for leaks too, as there has to be an explanation found for the thin and watered down appearance of the existing PS fluid. For replacement fluid, make sure to use the exact product Nissan recommends.