Sounds like the bearings may be on their way out on either of the two units. You can narrow it down with the use of a mechanic's stethoscope or, like my dad always did it, get a long screwdriver and put the tip against the unit and the handle in your ear.
If the noise changes only with accelerator changes then my first guess would be the alternator. If it changes with both the accelerator and steering input, then it might well be the P/S pump.
Mac
If the noise changes only with accelerator changes then my first guess would be the alternator. If it changes with both the accelerator and steering input, then it might well be the P/S pump.
Mac