98 GMC fuel pump problem...any suggestions???

I replaced the fuel pump in my GMC pickup with a Carter fuel pump from Oreilly's. The first time I ran it after changing the pump , the truck left me stranded at a lumber yard, as the fuel pump would not come on. Once I got it home, 3 hours later, I checked all the wiring and fuses. Nothing amiss. I double checked the wiring connectors and even ty-wrapped them to ensure good contact. Continuity checks were fine. Once everthing was back together it cranked right back up and I took it for a drive for 30 minutes. I never turned off the truck till I returned home. Once home and after turning off the engine, the fuel pump would not come on again. I left it alone till the next morning, and it cranked on the first try. I turned it off and it cranked up a second and third time without any problem. I took it for another 30 minute drive , got home, turned it off, and the fuel pump would not come on again. I replaced the fuel pump relay even though the old one appeared to be fine. The next morning it cranked up easily, once again, I took it for a drive and when I returned home, the fuel pump would not come on after shutting down the engine. Can anyone give me some suggestions as to how I can fix this thing????????????