1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

no power at the fuel pump!

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Old Jul 17, 2008 | 05:36 PM
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Enthu's Avatar
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MN no power at the fuel pump!

Recently the fuel pump just went out on the '79 SA. I got a carter and went to install. Tested for voltage with a DMM probe on the wires and then just the positive wire to a ground. There is no + voltage coming to the fuel pump.

What could possibily cause this? the car has been upgraded to an electronic ignition witha 2Gen coil and the transistor trick. I could just rewire, but it'd be nice to just find it was a fuse or something.

all the fuses look good, it has a 2nd gen fuse block too. Any ideas what could have gone wrong?
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Old Jul 17, 2008 | 06:59 PM
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trace the wire and check the continuity that will tel you if you need to rewire or were the bad conection is
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Old Jul 17, 2008 | 07:20 PM
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make sure you have a good Positive and ground . happened so i checked the wires and they werent touching each other
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Old Jul 17, 2008 | 07:34 PM
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Make sure you remove the fuel pump fuse and replace it with a known good one.
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Old Jul 17, 2008 | 07:52 PM
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The SA used the old glass fuses. Those can look ok, but still be bad.
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Old Jul 17, 2008 | 08:16 PM
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The fuses can still look good? really? alright, I'll change it just to be certain.
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Old Jul 19, 2008 | 01:25 AM
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This may be a stupid question, but in the wiring diagram it shows the fuel pump on a 20 amp fuse. My manual shows nowhere which fuse number it is, and there is no lid with a diagram on the fuse panel.

anyone know off hand what number the fuse is on the SA for the fuel pump? The Carter goes in tomorrow and I would liek to have the wiring sorted otu in the morning.
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Old Jul 19, 2008 | 12:30 PM
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just looked on my sons 79 it has the fuse panel lid but no luck fuel pump is not listed on it
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Old Jul 19, 2008 | 12:59 PM
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I got my pump on a toggle switch. My power went out at an autocross and babyed it home.
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Old Jul 23, 2008 | 06:18 PM
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Sounds like fuse issue.
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Old Jul 24, 2008 | 11:55 AM
  #11  
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Originally Posted by Enthu
Recently the fuel pump just went out on the '79 SA. I got a carter and went to install. Tested for voltage with a DMM probe on the wires and then just the positive wire to a ground. There is no + voltage coming to the fuel pump.

What could possibily cause this? the car has been upgraded to an electronic ignition witha 2Gen coil and the transistor trick. I could just rewire, but it'd be nice to just find it was a fuse or something.

all the fuses look good, it has a 2nd gen fuse block too. Any ideas what could have gone wrong?
you sure your fuel pump is bad?

You got me wondering............since I thought my fuel pump went out a while ago and while I know it's not getting fuel, I wonder if I have a bad wire or a fuse that sort of halfway blew.
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Old Jul 24, 2008 | 01:35 PM
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It's usually a red 10 amp fuse 90° from the usual orientation of the other fuses.
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Old Jul 25, 2008 | 08:10 PM
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I found it was a bad fuse! perhaps the dying fuel pump blew it, as the old pump was making very inconsisten tickign sounds. Jeff, the fuse that was blown was a green 20 amp that also powered the lead coil.

The strange things was, the car would start and the tachometer would work like the coil had power, yet it is on the same fuse as the fuel pump. granted, the car woudl only run for a split second upon start up as it had no fuel pump.

The bad fuse had an extremely small crack in the center of the metal piece that I could only see on very close inspection. I took it out and both the coil and pump had no power. put in a new one and then I had + voltage at the fuel pump. somehow the bad fuse still gave power to the lead coil. It's a mystery to me.

The fuel pump had some questionable looking wiring going to it, so I cut it away and and soldered in some new 14 gauge for it with heat shrink tubing on the solder joints.

the car is running happily with its new Carter fuel pump!
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Old Jul 29, 2008 | 10:54 PM
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tachs are for weenies
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From: mt. lebo, pa
Originally Posted by Enthu
I found it was a bad fuse! perhaps the dying fuel pump blew it, as the old pump was making very inconsisten tickign sounds. Jeff, the fuse that was blown was a green 20 amp that also powered the lead coil.

The strange things was, the car would start and the tachometer would work like the coil had power, yet it is on the same fuse as the fuel pump. granted, the car woudl only run for a split second upon start up as it had no fuel pump.

The bad fuse had an extremely small crack in the center of the metal piece that I could only see on very close inspection. I took it out and both the coil and pump had no power. put in a new one and then I had + voltage at the fuel pump. somehow the bad fuse still gave power to the lead coil. It's a mystery to me.

The fuel pump had some questionable looking wiring going to it, so I cut it away and and soldered in some new 14 gauge for it with heat shrink tubing on the solder joints.

the car is running happily with its new Carter fuel pump!

I'm going to have to check my fuses more carefully when I get a chance, if I heard of this half bad fuse thing before, I forgot it.
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