fuel pump won't prime on my gn please help

[SMOKINGV6]

If I power pump directly at the rear harness , it comes on. If i power up the grey prime wire behind alternator, nothing. I am getting power to the relay, I ordered a new relay becuase mines original, but it wont be here til tomorrow. The orange wire to the battery is hooked up, the fuses are all good. there is no aftermarket hot wire kit on it yet. the car came back from the body shop where they totally disassembled everytihing on the doghouse, removed, doors, etc , car was completely painted, but it had this problem the day i towed it to the body shop. It starts off staring fluid so I know spark is there. I dont see a ground strap on the tank, so I will add one . Any ideas of what else to check.? Maybe a missing ground by the ecm,??? thanks

 

[ttaowner]

i had a problem with one of my cars and i tried everything turned out the fusebox most of had a little corrosion it so after a few inand outs with the fuse fixed it. i changed the fuel the gas tank started leaking once i pulled the tank,swapped ecms.swapped relays, checked all kinds of other stuff turned out to be something stupid. hope this helps

 

[RmvBfrFlght]

The gray prime connector by the alternator bypasses the relay. It runs directly to the firewall bulkhead connector, through the interior, then through the connector in the trunk (left side, rear), then out through a grommet to the tank pickup harness connector.

There is another connector someplace in there, but I'm not sure where it is located.Hmm, it may be up by the firewall in the interior, to go from the main harness to the harness that runs to the rear of the car.

Through the interior the wire is tan/white. Then changes to tan (copper colored actually), after or at the trunk connector. Then tan/white again.

So, if the prime connector doesn't supply +12 volts to the pump, one of these connectors may be open. Or the wire is cut someplace along the way.

RemoveBeforeFlight

 

[SMOKINGV6]

Thanks for the help, the new relay is installed and still no prime. Im gonna start checking the wiring from front to rear like you suggested. If anyone knows where that connector is in the dash please chime in, thanks...Also can someone take a picture of inside trunk harness, at the left rear . the body shop did not re install it correctly so i had to plug it back in to get the tail lights working, but not sure which way that copper ground tab gets mounted.

 

[RmvBfrFlght]

A piece of my previous info is not correct. The color of the wire as it runs the length of the interior is tan, not tan/wht. This tan wire is more of a copper color.

Here is a better run down:

gray under the hood at the test connector
C100, firewall bulk head connector, pin G6
From C100 to C209, tan/wht
C209 is mounted on the left side of the fuse block, see picture.
C209, pin K, tan, about middle of connector. This wire (and the others on C209) run the length of the car and ends up at C320, which is the connector in the left rear corner of trunk, see picture.
C320, pin G, becomes tan/wht and exits the trunk through the grommet.

In the trunk connector picture, the wire of interest is the one that has the splices in it. Also, in the picture that wire is tan/blk, and is top most in the pic. I likely didn't have the exact color as I had to repair that section. A previous owner was using it to trigger a hot-wire relay in the trunk.



RemoveBeforeFlight

 

[SMOKINGV6]

Thanks for the pics and info, I see there is a pigtail that doesnt plug into anything, was curious what thats for.? I will check that feed wire for continuity from fuse box to rear connector.

 

[RmvBfrFlght]

Thanks for the pics and info, I see there is a pigtail that doesnt plug into anything, was curious what thats for.? I will check that feed wire for continuity from fuse box to rear connector.

The light blue connector to the right of the fuse block? I think that is for the cruise switch on the brake pedal.

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[fastblackracing]

I believe that harness connector in the left rear trunk corner has the fuel pump wires in it also I dont have my schematic book handy to tell you which wires but make sure that harness connector is 100%

 

[SFI Cutlass]

If I power pump directly at the rear harness , it comes on. If i power up the grey prime wire behind alternator, nothing. I am getting power to the relay, I ordered a new relay becuase mines original, but it wont be here til tomorrow. The orange wire to the battery is hooked up, the fuses are all good. there is no aftermarket hot wire kit on it yet. the car came back from the body shop where they totally disassembled everytihing on the doghouse, removed, doors, etc , car was completely painted, but it had this problem the day i towed it to the body shop. It starts off staring fluid so I know spark is there. I dont see a ground strap on the tank, so I will add one . Any ideas of what else to check.? Maybe a missing ground by the ecm,??? thanks

Are you saying you can start the car with starter fluid and will it stay running after that?

If you are only having fuel priming issue might want to also check the connector plug on the oil pressure switch. That plug has a wire that goes to you fuel pump relay and when the ignition is turned to the on position, it will control fuel priming on start up. Computer will see that there is no oil pressure and will let the fuel prime and then shut off.

 

[SMOKINGV6]

Ok, I got it started, messed with the feed wire at the fuse block, and at the connector, also removed, cleaned and re secured the contact at the ground wire inside trunk . Im not sure if it was from moving the wires or redoing the ground. Thanks for your help everyone, still would like to know what that 3 wire connctor inside left rear of trunk is for???? it has 3 wires and doesnt plug to anything. blue, black, and brown wire i believe. thanks

 

[SMOKINGV6]

The light blue connector to the right of the fuse block? I think that is for the cruise switch on the brake pedal.

RemoveBeforeFlight

no, the 3 wire one inside the trunk at the main connector like in the pic you posted

 

[RmvBfrFlght]

The light blue and black (ground) is for the 3rd brake light on the package tray. The brown is for coach lights, whatever that is (also uses the black wire). It is on whenever the tail lights are on. Maybe exterior lights on the C pillar?

RemoveBeforeFlight