have 2000 Dodge Ram 2500 4X4 cummings diesel....the power steering is going out when turning to the left and now seems to be having trouble when turing to right at times...no problem when driving straight only when attempting to turn?????????

You might have water or another fluid in the power steering pump. Prior to replacing the unit, I'd try replacing the fluid.

There's no drain plug that I know of, so you'll have to siphon the old fluid out. Replace with good quality ps fluid, and give it some time to work. Keep in mind that there will still be a good quantity of old stuff in there, so you may have to repeat.