No power to fuel pump relay.
#1
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Car: 89 5.7 IROC/95 LT1 Corvette
Engine: All 5.7's
Transmission: 700R4 (Roessler)/ZF6
Axle/Gears: 10 bolt Zexel 3.23's. CTW 17" wheel
No power to fuel pump relay.
My car will not start, began with a vats problem, finally got that sorted out now I don't have power to the fuel pump relay. Any help is appreciated. Thanks.
#2
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Re: No power to fuel pump relay.
The wiring diagrams hosted at AustinThirdgen show that the fuel pump relay receives the power that is switched to the pump from the body mounted fuse #2 , which will be one of the two fuses up near either the battery or the charcoal can . The power that actually energizes the relay's coil comes from the ECM on pin A1/C1 . Which power source (because there are two) were you referring to ? If no power on the dark green/white wire (relay's coil) then it's likely an ECM problem . If no power on the large orange wire (power for relay's switched contact) then it's likely body mounted fuse #2 problem .
PS , don't forget that one of the two body mounted fuses also supplies the ECM with some of it's power as well ....
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Car: 89 5.7 IROC/95 LT1 Corvette
Engine: All 5.7's
Transmission: 700R4 (Roessler)/ZF6
Axle/Gears: 10 bolt Zexel 3.23's. CTW 17" wheel
Re: No power to fuel pump relay.
Thanks,OB, I found a fuse that was up by the battery and it was good. I didn't check it for power though. I will check out AustinThirdgen and see if I can find anything new to check.
#5
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Car: 89 5.7 IROC/95 LT1 Corvette
Engine: All 5.7's
Transmission: 700R4 (Roessler)/ZF6
Axle/Gears: 10 bolt Zexel 3.23's. CTW 17" wheel
Re: No power to fuel pump relay.
Thanks John. It appears I have no signal at the C16 pin on the ECM.
#6
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Re: No power to fuel pump relay.
Ok , so , no +12Vvolts on pin C16 ?
Well , as you see in John's diagram , Pin C16 is fed power from the same fuse I mentioned earlier , Body mounted fuse #2 . It is supposed to be +12Volts on the orange wires , one of which feeds the switched contact in your fuel pump relay .
#7
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Car: 89 5.7 IROC/95 LT1 Corvette
Engine: All 5.7's
Transmission: 700R4 (Roessler)/ZF6
Axle/Gears: 10 bolt Zexel 3.23's. CTW 17" wheel
Re: No power to fuel pump relay.
Thanks again, OB. I'll look for that little SOB. I may not get to work on it again until Saturday though. Thanks for all the advice.
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#8
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Car: 89 5.7 IROC/95 LT1 Corvette
Engine: All 5.7's
Transmission: 700R4 (Roessler)/ZF6
Axle/Gears: 10 bolt Zexel 3.23's. CTW 17" wheel
Re: No power to fuel pump relay.
The body fuse is good, I found it behind the passengers side headlight. I am now looking for fusible link "D". Anyone know where it hangs out?
Thanks.
Thanks.
#9
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Re: No power to fuel pump relay.
All fusible links are attached to the big lug on the starter as far as I know . And don't forget , an open fusible link can look all frazzled if the short circuit that took it out was a "hard" short (something in the + line going straight to ground) , BUT ! , it can also be open and look just like all the others (non melted insulation) if the failure was , for instance , mechanical vibration that caused it to flex a zillion times and then break the wire inside (while leaving the rubber insulation intact) .
#10
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Car: 89 5.7 IROC/95 LT1 Corvette
Engine: All 5.7's
Transmission: 700R4 (Roessler)/ZF6
Axle/Gears: 10 bolt Zexel 3.23's. CTW 17" wheel
Re: No power to fuel pump relay.
Copy that. Can these just be tested for conductivity? And if I replace it what is it rated at? Thanks again.
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