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Fuel Pump relay energize pin?

Old 03-19-2011, 04:02 PM
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Join Date: Mar 2011
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Default Fuel Pump relay energize pin?

I just joined and I have a 97 half ton Vortec 5.7 and a 01 Duramax HD2500.

My situation is that the 97 sat and sat for almost two years and was started here and there. It did remain almost empty on fuel for that time because I wanted to keep getting some fresh fuel in there here and there.

Well, I went to park it out of site before last winter started and I saw that it was very very low on gas so I had it running and was walking up to it with a gas can and it started to sputter and die. I ran to try to get some fuel in there but was too late. It died and after I put a couple gallons in I was ready to just start it back didn't start.

I had an 88 truck too and had noticed that the relay box under the hood was in the same place so I figured it was very similar in the basic wiring minus the TBI vs. Vortec.

I had found a no start problem when I had the 88 to be the horrible ground to the frame for the pump "module" so I thought that I would get lucky and removed and cleaned up the ground (on the 97) and still no start. BTW this 97's pump was replaced as a module because the pump died from normal use and I had lost the fuel gauge. This I had to pay for and it was painful to pay but I was hurt at that time.

I checked the ground "eyelet" off the tank to battery negative and got voltage reading when cranking. To me, this means the pump is getting power but the pump (even being almost new) was stuck so to speak.

Finally my question.

Does anyone know which pin (female) of the five pin relay can I apply voltage directly to. My idea is that if the armature is sticky/stuck that I can kind of keep tapping a higher voltage to it and maybe get it turning and be done with it. What I mean with higher voltage is hooking up a jumper set form another "running" vehicle and use the running 14 volts or so over the cranking voltage it gets which is 10-11 volts.

If someone knows, it could just be explained as leaning over the drivers side fender and which of the 5 pins is it. I know it must see oil psi to keep running but I just want to not have to pull that pump and the oil pressure goes up right away when cranking anyway.

Anybody making any sense of that, and knows how to directly feed that pump voltage would be great. It's the only relay on the block that has 5 and not 4 pins, so you could say "row of pin, or 2 pin side...the one closer to the drivers side etc.

Sorry for rambling first post, but it's the best way to visualize it I can think of.

And lastly, is there posts here about either removing the bed if I have to to get to the pump or I've seen elseware that you can remove drivers bed bolts (3) and loosen pass. side bolts (3) and jack up/prop up the bed a bit to get at the top of the tank.

Thanks a lot

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