88GTBlack

96 xj low voltage problem at fuel pump. I want to run a 12v power supply back there so i can get fuel pump to run.

What color wire powers the fuel pump out back?


What color is ground? I had a mice problem and feel thats the culprit.


Runs on starting fluid

88GTBlack

Bump. Low volts at fuel pump

88GTBlack

BUMP!

12V cranking at fuel pump

5V steady with key on

fuel pump does nothing

must be ground issue.

I need a pinout of wires, or wire colors, or some sort of schematic. so i know where ground wires are where 12V hot should be.

comeon guys!

fuel pump worked perfectly 2 months ago. I had a rat problem in that 2 month period a few wires got chewed under my seat. they got in from when i did mu clutch. and the shifter was out. i fixed the broken wires i saw. but any help is appreciated

Slick761

I'll subscribe and tell you when I get out there. I know orange is constant power from the resistor which is the 5v your getting. One wire can't remember the color is 12v prime and the other is the sender. Pretty sure the pump is grounded to the tank

88GTBlack

thanks let me know im lost here.

Slick761

Could be coincidence and your pump may be dead. I have to put up some Xmas lights. If I don't fall off the roof ill check it out when I'm done.

ET JEEP

Looking at a diagram for 4.0 engine there are 5 wires going to the fuel pump module.

1. Relay output to fuel pump module Dk Grn/Red (This is the power)
2. Sensor Ground PCM to module Blk/Lt Blu
3. Fuel Level to Instrument Cluster Dk Blu
4. Low Fuel to PCM low fuel sense Dk Blu/Wht
5. Ground Blk

dalthanar

It seems you are thinking a chewed wire is the issue, but any time you have a fuel pump issue, first check the relay. Mine went bad, and I at first checked everything but that. Swap the fuel relay with the fan relay. See if you get a different response. Worth a shot.

CrawlerXJ

What color wire is from fuse box in engine bay for fuel pump? Fuse 16 I think.

If there is another easier route to tap the wire inside Jeep. I am all ears

RTorrez1

Did you by any chance notice the original post date?
I was going to leave a post until I noticed the original date 12-04-2011

88GTBlack

LOL

I fixed it and scrapped the rig, floors were gone nothing was good on it.

The problem was the ground wire from harness going to the ground pin on outside of sending unit was just bad from corrosion. I cleaned a new spot and soldered a new ground right to it and havent had a problem since. Thanks though guys.

CrawlerXJ

I did.

Been online since 94 or so. I noticed you have those who **** OP didn't search before post. Then those who think the world came to end if you post on an old post. Someone is always going to complain. lol. Can't win.

Did you know the answer?

ET JEEP

What year, model and engine? I will check the diagragm if I have one.

Slick761

So true

crhea

OK, it's 2017, but there are STILL some of us who have older (ancient) Jeeps.

I just recently took my 1994 GC Limited out of storage and am trying to get everything
healthy again. So yes, while it was a hot topic back in the 1990s, there are those of us
who are still actively looking for how to diagnose and fix fuel tank senders.

So for those who answer old posts-- even years later-- THANK YOU.