Stiff steering 2005 Dakota

I have a 2005 Dodge Dakota truck. Recently the steering wheel has become stiff. It seems to come and go. The power steering will go from
hard to easy in a single turn. The fluid level is fine and the belts seems plenty tight. The pump & belt don't make any bad noises. Any Ideas would be greatly appreciated.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file
Upload is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.