There would be a fuel pump fuse, either under dash or under hood. Check that fuse, use the test light to see if fuse has power. If not, then it might be a fusible link or maxi-fuse that feeds the fuse panel. If fuse has power with key on, pull the relay, and use the test light and probe relay terminals, key off. One terminal should be hot at all times. If not, check for power loss between battery and relay terminal-possibly a maxi-fuse or fuse link.
If relay does have power to terminal, quickly check other terminals while someone turns key to on-for about 2 seconds, another terminal should show power-this would be signal from computer to turn the relay on to prime the lines and fuel rail. If you have that, plug relay in and cycle key. Does relay click? If yes, relay is working and problem may be at fuel pump connector. If relay is not working, but you have power to it, and the short signal from computer is there, then check the relay's coil side ground. Computer signals the coil side and the signal goes to ground from relay coil side.
Pull the relay and use a jumper wire from relay's hot terminal to fuel pump terminal-the wire to pump from the relay. If pump comes on, the problem is right there at the relay-either no signal from computer or the relay coil's ground is lost. If pump does not come on, again check connector at pump-that or the wire to pump[ has a problem.
The fuel pump and the sending unit are on two different circuits. The sending unit grounds the gauge. The pump gets power from the pump relay when you turn the key to start.
Looks like orange-black is power in and purple is signal out for the sending unit. ( may be opposite ) Gray is power in and black is ground for the pump.
And the pump is only powered for 3 seconds when the key is turned on.
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SOURCE: 2003 GMC Yukon - fuel pump
Check your ECM fuse. There should be 2 fuses for your ECM. It's the ECM that controls the function of the fuel pump. Good luck friend and it's also common for the wire harness from the frame to the fuel pump to go bad due to corrosion from the bad weather we get in the winter and rainy spring and fall.
SOURCE: 2001 yukon, new fuel pump not working
OMG! I googled my problem and your posting popped up and mine was the same to the T. I changed that fuse and it started and runs like new again!!! Yay! I know my fuel pump was out but was confused when I couldn't figure it out. These are amazing vehicles and I'm glad I own one.
SOURCE: I have a1994 gmc Sonoma. Fuel pump fuse keeps
The only other things on that circuit are your PCM(power control module) and the fuel pump/oil pressure switch. You can start with that but it is more than likely a ground somewhere on that circuit. If this helped four thumbs up please.
SOURCE: Need help replacing fusible link connector
It doesn't matter because they all carry +12V to the respective circuits. What does matter is which fusible link goes to which circuit (assuming they are different) but if you didn't cut them off, then they should still be connected to the correct circuits.
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