Power Steering Pump whine?

Today I started the Taco at like 8 am after it rained for like 5-6 hours and this loud low tone whining noise appeared. It gets louder as the rpms go up and it sounds like a power steering pump but the fluid is relatively clean it's only got 86k miles. I looked at the pulleys and tensioner and they are good. I still have power steering. Just loud and wondering if I can put conditioner to help it. Tia

 

Does it sound different when you turn the wheels left and right? Should whine more. Could be anything spinning on the serpentine belt like alternator, AC compressor, idler puller. You need a stethoscope to pinpoint the exact location and cause. Harbor Freight has a $5 one.

 

Rule out PS pump by turning the wheel, rule out the AC compressor by turning it on and off. Possibly rule out alternator by changing electrical loads(not surefire by any means but heavier load say from headlights and blower on high may intensify it).

does it go away when the truck warms up and/or dries off? If it was a hard driving rain maybe some water got on the fan/pulleys?

And yeah, if it persists, you can get a stethoscope for like 10 bucks from Napa. just be reeaaal careful where you stick the probe around the belt while it's running. if it's that loud you may be able to hear where it's coming from just by popping the hood and listening