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Hi I have a 1980 Chev Luv with a 4cyl the fuel pump only works wile its cranking when you turn the key to the run position the engine runs till it runs out of gas in the carb if I put power to the fuel pump wire the engine cranks anyone have any ideas?

Fuel pump relay? Its under a tin cover up against the firewall on the passenger side. Its there as a safety feature so that the fuel pump doesn't keep pumping gas in an accident. See what happens if you unplug it and wire across the leads.
I wouldn't leave it out long term.

Do the fuse box fix too. The fuse that is labeled "regulator" also controls the fuel pump and the coil. Many luv issues trace back to the fuse box in ways that are unpredictable.

When I got my first luv my grandpa said, We need to put a Wiring Kit in it or you'll have electrical problems the entire time you own it lol. So I rewired it and It hasn't let me down yet in the electrical dept.

That's the opposite of what the pump should do. They don't run when cranking (which seems odd to me, but that's what I have found) and it should (obviously) run when the eng. is running.

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OK, I'm over it. Where's the beer?

No that is the purpose of the relay, The NCC is connected to the start circuit, powering it as long as the key is in the start position. Once you release the key, if the alternator is charging, the voltage regulator powers the relay coil connecting the fuel pump to the NOC which is hot. Of course, power needs to be making it through the contacts of the fuse box, which can fail.

Not meaning to hi jack, On my 4X4 the pump won't run when the key is in "start". I'll have to look into this. Maybe a bad relay.

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OK, I'm over it. Where's the beer?

That is correct. Good explanation, or at least that is how it is supposed to work.

Hi as an update the relay seems fine but wile its running the gen light is on and charging at 16 volts would a bad voltage regulator make the fuel pump not work in the run position?

Yes it can. The fuel pump relay gets its power from the regulator---the white/red wire.

Hi thanks for all your help the problem is fixed a new voltage regulator fixed the problem maybe someone with the same problem will see this and it will help them

Yes, posting what worked can help the next guy. Thank you. The C light and fuel pump relay coil both run off that red/white wire.

Yes thanks also for posting back. On these trucks when the charge light comes on get ready for the engine to stall.
A tip: If you disconnect the plug at the regulator when this happens you usually can restart the truck and get it home.
The current path for the charge lamp to ground is through the fuel pump relay coil and this will many times be enough to close the relay and operate the pump.