ECM output

[bowtie65]

hey...I have a 1990 k1500 5.7 auto 4x4....i am rebuilding this truck and just about everything is new,,the truck was running and all of a sudden its wont start..I started checking fr power and there is 8.45 volts at fuel pump connector ..power at pin going into the ecm (read thats were the pump gets it signal..so checked what i could find. I have no power at the pump fuse on the fire wall and power at the the pump relay..so im totally confused any suggestions where to look next

 

[Schurkey]

there is 8.45 volts at fuel pump connector

WHICH "fuel pump connector"??? Are you talking about back by the gas tank?

..power at pin going into the ecm

WHICH "pin going into the ECM"? There's lots of pins at the ECM.

I have no power at the pump fuse on the fire wall

Trace that circuit first. Download the service manual set for your vehicle, follow the wiring diagram(s).