1993 Chevy Astro power drain

1993 Chevy Astro 6 cyl Two Wheel Drive 100000 miles

after trying to jump my husbands car. I went to work and my car would no start. 2 hours later it did
. After a couple days of it acting haywire. I noticed that there was a whining noise coming from the area of my fuel pump, when you turn the key over the whining stops. If you walk away then the noise will come back, and the battery will be dead, so I guess the first question is can a fuel pump draw power when the car is off and the key is out, second why. And what else can it be, the fuel pump is less than 2 years old