help - '97 astro fuel pump noise

I just purchased a '97 Astro that had a noisy fuel pump. The pump gave out a few weeks after I got it.
We pulled the tank and replaced the pump with a new one. It worked fine and only made a little noise.
The noise has gotten louder over the week since it's replacement. I fear that something is causing the pump damage and shorting it's life.
Anybody have any advice or Knowledge on this?
The noise changes pitch when I flip the heater fan switch from HI (that doesn't work) to Med Hi (that works half the time).
Is it possible that a short in the electrical system could be causing problems with the pump?
Thanks
Steve

The only thing common I see between the blower motor circuit and the fuel pump circuit is that they both have fuses/relays in the underhood fuse/ relay block. Are you positive the noise is coming from the fuel pump? Do you have rear heat in your van? Could this be the rear blower making the noise?

Did you replace the pulsator when you replaced the pump. We've seen a rash of failure of those around here. Make sure you are running with more the 1/4 tank of fuel at all times as well. The pump uses the fuel in the tank to keep itself cool. If you are running around low on fuel, you will burn that new pump up quick.