no power to fuel punp

My 98 hoe is ****ing with me seriously. I jus changed the fuel pump a week ago and the relay. Today on the highway truck started to stall and gas guage dropped to empty (a quarter tank of gas in the truck). Once I came to a complete stop truck shut off and wudnt start. Relay was hot so I changed it still no start. Tried to jump it from the relay and nothing pump not cutting on. I jumped the grey wire directly on top of the pump and pump turned on. And I can start and drive but gas guage still on empty. I tested the grey wire from the trucks wire harness that goes to the pump it reads a 4.8 volts. Jus like the purple wire. The ground is good. And idk what the lil black wire is for. Has anyone ever witnessed this problem? I know the pump works and relay is good so what else can cas this problem

I am new to the forum for a similar reason. I shut off the truck at a store last Sunday. When I got in to head home the Tahoe would turn over but not fire. I assumed the fuel pump went bad since it seemed to be getting louder the past few weeks. I changed the pump and rewired the connector (this truck came from Texas and is like new underneath), so I am not sure the "corrosion" problem in the connector would have been an issue. I also change the fuel relay after it didn't cycle when trying to prime the system.

Nothing, no pressure at the Throttle body, no whine of the pump with the ignition turned on. I jumped the old pump with a battery and it cycled so I am not convinced the fuel was at fault to start with, even though it looked to be the original and the vehicle has 184k miles on it.

The Passlock issue that seems to plague some owners does NOT presenting itself, I am not even sure mine has a chipped key. The security light come on and goes off after 4-5 seconds and does NOT flash.

I hope this thread gets a few replies with some ideas.

Thanks

find my problem

Ok so some how the wiring under the truck jus died I had to rerun the grey wire and the purple wire w/ the white strip from the front of the truck past the clip under the break booster and cut off the existing wire

Mine ended up being a fried PCM. Something shorted out inside. Not only was the fuel pump not working, the EGR valve was staying engaged, draining the battery. I ended up finding one at a local junkyard with the same service code and had a independent mechanic flash it. It cost me 35 for the PCM and 50 to flash.

Nice....
The passlock system in use uses a resistor in the cylinder not the key...... So you wouldnt technically have a "chip" in the key......