Fuel pump not engaging

136,000 MILES • V8 • 4WD • AUTOMATIC
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FELON325
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When I turn the key, my fuel pump doesn't engage. there is about ten gallons of gas in it, and it's a new pump, what now?
Apr 22, 2011 at 11:20 AM
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RASMATAZ
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Check the fuel pump fuse, fuel pump relay and the ASD relay
Apr 22, 2011 at 11:31 AM
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FELON325
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Fuel pump relay? ASD relay? forgive me, I'm trying to teach myself as i go, NO MECHANICAL EXPERIENCE!
Apr 22, 2011 at 11:35 AM
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CARADIODOC
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The fuel pump only runs for one second after turning on the ignition switch. You should be able to hear the hum. If not, listen by the tank while a helper turns on the ignition switch. After that first second, the pump will run again during engine rotation, (cranking or running).
Apr 22, 2011 at 12:29 PM
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FELON325
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Yeah that's my problem, there is NO hum, not a bit!
Apr 22, 2011 at 1:05 PM
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CARADIODOC
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You can try banging on the bottom of the tank while a helper cranks the engine. GM fuel pumps commonly fail while driving and let you sit on the side of the road. Chrysler pumps rarely quit while driving. They typically fail to start up due to worn brushes in the motor. Banging on the tank jars the motor a little until the brushes make good enough contacts to start the motor spinning at which point it will keep going.
Apr 22, 2011 at 1:41 PM
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FELON325
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Tried that, before AND after I changed the pump. I think it's electrical, somewhere in the wiring, or a connecter, but I can't find ANYTHING that is bad!
Apr 22, 2011 at 1:59 PM
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CARADIODOC
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Look for a dark green / orange wire in the connector for the ignition coil or any injector. Measure the voltage on it for the first second after turning on the ignition switch and again during cranking.
Apr 22, 2011 at 2:03 PM
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