Chevrolet Repair Questions? Ask a Chevy Mechanic for Answers ASAP
According to this diagram the fuel pump is fed through the grwy wire coming off the relay. If you say you only have voltage at orange wire at relay then I would say the relay is bad.
Leave the harness hooked up at the fuel pump relay and make a jumper wire that will fit into the back of the harness and with power at the orange wire jump it to the gray wire. Do you hear the fuel pump kick on? If no.
Make sure the fuel pump works from the diagnostic connector.
Take a small piece of wire and strip both ends and insert into terminal "A" and terminal "G", you may need to turn the key to run. Does fuel pump kick on?