Which one? You should only be concerned about the Tan w/white one. That is the voltage feed to the pump. What is that wire doing?

 

The third wire should be for the fuel level sender. If the wire you're seeing switched voltage at is the Tan w/white wire, and there is no pump prime noise, you pump is dead. Replace. Done.

 

..i wonder WHY he won't apply 12v to the aldl?

 

If you determine that the fuel pump is bad, replace it with the OEM. Don't purchase an aftermarket pump or you will be replacing it soon. Also, when you remove the old fuel pump, make a note of the location (orienatation) of the sock and make sure you reinstall it the same way. The OEM's have tighter tolerances than the aftermarket.

 

The "and other I don't know" wire is for the fuel gage sender unit.

 

Well I will che the tan wire today! The fuel pump was replaced about 2 yrs ago and it has bout 50,XXX miles on it!

 

The patience shown here is amazing!

 

Well the one with wire with power is a redish pink wire... Im guessing this is the fuel sending wutever wire? I put power from the battery to the g wire and still the tan with white has no power! Im gonna go try to jump the reley wires right know!

 

....if you run power to the aldl like everyone is telling you and the pump doesn't run, then you have defective wiring or a bad pump... ...

...i am not sure if it is possible but, if you run power down the wrong set of wires into the fuel tank assembly, (w/o having looked at a diagram myself), i would believe that a short or spark wil occur in the tank and an explosion will result ......i could be wrong as i don't have a diagram in front of me now.....

 

It want make a difference if you jump the fuel pump relay wires if you ran a 12v wire to termianl G and you have no power at the correct wire at the pump.

If you had terminal G powered and you tested the tan/white stripe wire with a good ground and you get nothing....then you have a power supply problem or the wiring at the ALDL is faulty.

You can test it several different ways.

1. Power terminal G and you should have battery voltage at the tan/white stripe wire. Use a test light or volt meter and make sure you have a good ground. Double check the fuel pump fuse (FR 10 amp) with a test light after the key is turned "on" but it will light up for only 2 seconds. The tester should stay lite when terminal G is 12v supplied.

2. Jump the fuel pump relay and turn the key "on". Be quick or have someone at the pump wires ready to test because 12v will only be supplied for 2 sec.

3. Pull up another vehicle and run a jumper wire from the pos and neg of the vehicle. Touch these wires to the connector going to the pump (tan/white stripe and black). If the pump and wiring at the pump is good, then the pump will run.

4. Remove the fuel pump out of the tank. Use the method above and touch the fuel pump directly with a 12v and a ground. If the pump is good, it should make a noise.

Can't make it any easier for you. Make sure to use common sense when dealing with a possible spark and fuel vapors.

 

 

I jumped it at the relay and I got power back there! But the Fuel pump does not come on either! Could it be that the fuel pump went out and also shorted the relay? (blew it as if it were a fuse?)

 

Replace the fuel pump relay, but last. Go ahead and pull the fuel pump. Test the fuel pump as described above with it out of the tank and after the gas has dried up. If the fuel pump does nothing when 12v and a ground are applied directly to it.....then stick a new fuel pump, sock, and strainer in the tank and call it a day.

 

........

 

One last check on the relay connector. Test terminal B for ground. See if you are getting battery voltage at terminal C when someone tries to start the car. If there is voltage then go ahead and replace the relay. If no voltage, the relay won't work even with a new one if terminal C is not giving the relay current to close, or if B is not grounded. Trace the green/white wire if no voltage at terminal C.

 

Well the thanks to all of you my car is now running! The relay was bad after checking the connectors B and C! After that I applied direct power to the fuel pump outside of the tank... the fuel pump was bad! So I put a brand new genuine ACDelco fuel pump!

 

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Running your vette with less than a 1/4 tank of gas will burn up that pump in no time.. NO MATTER HOW NEW THE PUMP IS! I keep a spare pump on hand at all times. Between my dad's 3 C4's he has had & my 2 C'4s we have replaced 7 fuel pumps. 5 OEM 2 OEM autherized replacements