I need some help. I have just bought my son a 2003 Ranger Edge it has a 3.0 auto. When i bought it the fuel gauge was not working. The person i bought it from said they have had the fuel pump replaced around two months ago and that the fuel gauge worked before it was replaced. So today i decided to work on it. I removed the bed and as soon as i look at the wiring from the fuel pump (look at pictures) this is what i saw.I removed the jumper wire and the truck would not start.Any ideas why the fuel gauge wouldn't work.

 

I would find out who replaced it and why that black wire is T-ed into the wiring.

 

The black wire is a jumper wire. It's jumps between the red and yellow on the wiring harness to the solid red on the fuel pump side. If you take the jumper wire loose the truck want start.

 

The colors dont look like the match are there any more splices?

How long is this jumper wire? I am having hard time following this wire.

The yellow/white is the signal wire for the gauge. To test the truck side wiring/gauge, get a 150 and a 15 ohm resistors from Radio Shack. Place them between the yellow/white and ground. 150 should read just over full and 15 just under empty. This is about the only way you can see if the truck works and that this jack wagon repair is wrong.

Also that pump looks like it is the wrong one for the truck, a direct replacement does not need jumpers.

 

There are no more splices. The red with yellow is jumped to the red on the fuel pump.I think maybe the wire going into the plug is messed up. I think this is why the have the jumper wire. Which wire is the ground in the wiring harness? Do you have the wiring diagram for this truck?

 

The black wire is the ground in the factory harness.

I do not have a manual for your year but have one for an 02, I can get you a pin out diagram if you want one. I just need to know if you are flex fuel or not.

Also typically the fuel pump is powered by the pink/black if I remember correctly. As that wire is the correct size to feed the pump.

 

I used the resistors to check the gauge/truck wiring it checks out ok.So there is something going on with the fuel pump. Is there anyway to check the fuel sending unit/fuel pump?

 

If you use a ohm meter you can read the resistance from the pump assembly. You need to pull the pump to cycle the float though its range. To see your full reading and empty. If you don't get close to the same values from the pump assembly odds are you will have to replace it as they don't just sell the sender.


If it is reading high, say off by about a quarter tank. Odds are power feed though the fuel sender frying it. I have first hand experience with that and have 2 bad pump assemblies with that issue. My truck had wire chafe issue in the harness under the drivers seat. It fed power into the sender then it started blowing fuses. To bad I changed the pump out before the it started blowing fuses.