Chevrolet Repair Questions? Ask a Mechanic for Answers ASAP
Hello I will help you with your question,
Where in the wiring is this wire?
On the engine harness? Under the dash?
OK, is it leading to the fuel pump relay on the fender?
Can you post a picture?
Does the truck run?
That is the fuel pump test connector, It does not connect to anything but it shoulod splice to a wire to the ECM that lets it know when the fuel pump relay is closed and sending power to the pump.
It sounds like you have a security or computer issue if the pump does not turn on and you don't have injector pulse.
If you want to pursue the no start post it as a new question. The wire is the pump voltage test connector and you can activate the pump without the pump relay as you found.
Let me know how I can help