power steering

the power steering in my 96 sable seems to be going out, there is plenty of power steering fluid, the steering feels loose at first then gets really tight and hard to turn, do I need a new power steering pump.

also the heat does not seem to be working, i belive this is due to a thermostat, the engine tempreture senser inside the console stays towards the could mark, it moves up a little bit, it is about a quarter of the way to the middle.

any coments are apreciated
thank you

I am a little more use to altimas.net forums with more info if any one knows of a better forum for this vehicle, or other links that would help/picks that would also help.