1996 Chevy Truck Fuel Pump Short?

1996 CHEVROLET TRUCK
167,000 MILES • V8 • 4WD • AUTOMATIC
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RUSTYCHEVROLET
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I have a 1996 chevy k1500. One day the starter went out on it, and I changed it only to discover the fuel pump had gone out as well. I replaced it with a brand new one. I also changed all of the fuses related to the fuel. However, the fuel pump will still not operate. I got a ohmeter and there is power leading to the fuel pump and on some of the wires on the fuel pump itself, but no power to the ground wire. I tried to re-ground the wire to the frame of the truck, and it ran for a few minutes, so I tried to test drive it and made it about 3 blocks and broke down again. There is no sound at all coming from the fuel pump. All of the ECM fuses are fine. Any ideas where this short might be stemming from? I had a similar 96 2500 that was 2 wheel drive that also ran on CNG and had similar problems. I did not find or fix the problem with the first truck because it had a cng short and caught fire. Any help would be appreciated. I'm tired of breaking down in this truck.
Mar 27, 2008 at 4:29 PM
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RASMATAZ
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The computer energizes the fuel pump relay for 2 secs then it de-nergizes unless the computer sees a cranking signal. Test the fuel pump relay. Below is how the fuel pump is wired in-


https://images.2carpros.com/forum/automotive_pictures/12900_oil_sending_unit_and_fuel_pump_circuit_38.gif

Mar 27, 2008 at 4:50 PM
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RUSTYCHEVROLET
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I actually bought a new relay switch and installed it at the same time. Still nothing
Mar 27, 2008 at 4:54 PM
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RASMATAZ
  • ASE Certified Mechanic
  • 75,992 POSTS
  • ASE Certified Mechanic
Check pin B3 at F/P relay dark green and white wire for power nothing there its coming from the computer fuel pump control relay- see below


https://images.2carpros.com/forum/automotive_pictures/12900_fp1_3.jpg

Mar 27, 2008 at 6:42 PM
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