GMC Denali 2001 fuel pump problems

I am a new member and I was wondering if anyone could help me with an issue that I am having with my 2001 Yukon Denali XL fuel pump. I bought it used last February and it ran real well for a while until one day in June it conked out on me and would not start. The original diagnosis was that the fuel pump had gone bad, so I had it replaced (by a family friend-no warranty) and it seemed as if we solved the problem. Well, a few months later the car conked out on me and would not start again. When I turned the ignition to ON position, I could not hear the fuel pump kick in which indicated that there must be some problem with it getting power. We checked the relays and the fuses and even "jumped the relays" to see if they were bad and everything checked out good. A few weeks later I went to crank the car and it started and ran well for a few weeks after which it conked out on me again. Ive been doing research on this and Ive come to these final conclusions:
1. There must be a short in the wiring to the fuel pump somewhere
2. There may possibly be a problem with the computer

Is there any other troubleshooting that anyone may know of that I can do before I drop this tank!!

Thank you for you assistance in advance.