98 3500 fuel issues

Shut the truck off one afternoon to check brake lights,never to start again.Pump was replaced recently.Turn the key on ,no pressure.No power to control side of relay.Jumped 87 and 30 in circuit and pump runs,56 psi. Fuel gauge is freaked out and goes way past full when key is turned on.So connected a scanner and it fails to link to the truck.When problem first occurred I had spark to engine and now aside from fuel problem I have no spark.HELP Im really at a loss here. I tested and retested all fuses.The fuel relay circuit grounds test good.Changed relay. any suggestions?

What engine is in this truck, 454 Vortec?

In the "underhood fuse-relay" center check these fuses for power in both the "start" & "run" position.

Pull the starter relay so the motor Is not spinning while checking this.

1. IGN-E 10a
2. ECM-1 20a
3. ENG-1 20a

If there are any power issues on these fuses, replace the Ign Switch.

Shut the truck off one afternoon to check brake lights,never to start again.Pump was replaced recently.Turn the key on ,no pressure.No power to control side of relay.Jumped 87 and 30 in circuit and pump runs,56 psi. Fuel gauge is freaked out and goes way past full when key is turned on.So connected a scanner and it fails to link to the truck.When problem first occurred I had spark to engine and now aside from fuel problem I have no spark.HELP Im really at a loss here. I tested and retested all fuses.The fuel relay circuit grounds test good.Changed relay. any suggestions?

my guess is the PCM/connectors @ PCM or the grounding points .