somethings running after i shut off my truck!

yesterday, I replaced the wire that runs from the ignition to my rotor cap, because the old wire had a short in it, and wouldn't turn over. Last night I took my truck to my girlfriends house, and I got out, and noticed a noise, it sounded like something running towards the rear driver side of my truck. It stopped after about 20 minutes or so. we went out, and the noise was there again after I turned my truck off, and again, about 20 minutes later it stopped. That night, it was making that noise for about an hour. I had my dad look at it with me and he said it sounded like it would be the fuel pump, from the location of the sound. It proceeded to make that noise for about an hour or so , so I went out, turned my truck on, and just gave it a little gas while the truck was parked. It stopped.
Right now I am at my school, and my truck was making the noise when I left it to go inside the building,



If anyone knows whats going on I would greatly appreciate any help or knowledge, if anyone has had a previous experience with this same type of thing, I would love to hear how it was handled. thanks so much

Replace the green fuel pump relay under your hood on the drivers side inner fender. It is sticking and causing your pump to run. Happens all the time. To test it, if it is shut off and pump is running just smack the relay and it will quit.