I have a 1995 Chevy K3500 5.7L 4L80E. It's 4 door with power windows, power locks and AC. I'm having issues with the truck starting for some reason the fuel pump is not coming on at all I've switched pumps switch relays and the pumps and relays are not bad. I've even run direct power with an alternator from the battery to check at the relay and at the plug for the pump and the pump will kick on. I've even bought a new ECU and that still has not made the pump work I'm not sure why the pump isn't working. The truck will try to crank and turn over and turn over or just not start because the pump isn't turning on to send fuel. I've checked all the fuses under the hood and inside the cab none appear to be blown.