Concerned about my '93 Supreme

A week ago when I started my car there was this high pitch hum coming from the car and now it's getting a little bit louder. I can place this sound from the rear where the fuel tank is. Could it be that the fuel pump is about to go on the fritz?

If you want to test the fuel pump, then ground the wire that appears to be hanging there, connected to nothing, between the air fiter housing, remote + terminal, and the cruise control vacuum module.

This procedure is outlined in the GM Manual as well as a Haynes manual.

Since the fuel pressure regulator is closed, the fuel is actually pumped back to the tank.