This truck new engine , pcm , fuel pump replaced . Silverado 2000 with key off some x no power to fuel pump relay but power to fuse that should only be hot with key on are hot. After sitting I’ve tried and good back to normal thought it switch was bad , then after setting today no power fuel pump again but all others hot then when I jumped gray wire from fuse box to pump it came back to life and started with no jumper what can this be. Help please bcm , or switch pcm new and fuel pump new