Stiff power steering, the pump or ?

[Tonyfeb14]

My 2003 4.4 X5 power steering is starting to feel very sluggish/stiff. Just not as light as it should be. Fluid level is good. The alignment might be off, little more tire wear on outside edges, so will take care of that. All bushings and ball joints are good, with new control arms just installed. The steering was getting stiff before I replaced the ball joints. Does anyone know how to test if this is the power steering pump or the rack and pinion that’s is going bad? The pump looks straightforward to replace. The rack is a bigger job requiring supporting the engine while dropping the subframe, so not something I want to tackle if I can test first.

Thanks, and always, great information and insights on this forum.