My 1993 lexus es300 is overheating. one mechanic said that it was the water pump. another said the power steering pump, who is correct?

The power steering pump would have nothing to do with the engine overheating but the water pump certainly would, but before you go to the trouble of replacing the water pump you need to be certain that is the problem as there are other issues that can cause overheating, like the thermostat or a blocked radiator, the mechanic who said it was the power steering pump quiet obviously don't know too much about engines............hope this helps......cheers.