Need a diagnosis please. Past few days, I have noticed a loud moaning (for lack of a better word) coming from the engine when I turn the wheel to either side. The sound occurrs not just on start up but the entire day. The power steering resovoir is about 3/4 full and fluid seems to be swirling in there. When I listened more closely today, I can hear a metal rattling sound as well. Just this morning, the AC started blowing warm air and I got the ABS three amigo light. I have a 04 Discovery with 73000 miles. I have never flushed the power steering system. My initial guess is that the pump is not working but I'm confused as to why the ac shut down and I got ABS lights. Any thoughts/advice would be greatly appreciated.

Reza