Looking at a '94 Mercury Topaz. It works great and has just been safety inspected. When l took it for a drive l noticed a noise as l turned the whel to the left or right. Kind of a light grinding. Just noticed it while l was sitting still. Not while driving. Thanx

could be air in the lines
or fluid low
see any spots under the car?

turn the wheel back and forth ( L and R ) while sitting, then look into the power steering fluid reservoir to see if frothy or low

bad power steering pump. costs about 600$ with parts and labor.

l wish l could hear the noise! It would be so much easier to have an idea of what it may be by hearing it. l would think if it had to do with the power steering, it would make more of a groaning sound, rather than a light grinding sound. One other possibility may be that the noise is coming from right at the steering wheel, depending on the noise. Especially if it was pretty hot inside the car at the time. There r only a few things that could be making the noise it seems. Either the steering wheel, steering shaft, steering box, power steering rack, or power steering pump.

add fluid to the power steering pump its most likely low