Diagnostic Info

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jotin

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2003
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If anyone ever needs diagnostic info I can get whatever needed. I'm a tech for dodge here in north Dallas.
I specialize in drivability, electrical and a/c.
Feel free to hit me up for stuff!


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Core-Lokt

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2005 Ram 2500 4X4 ST
Engine
5.7L
Thank you for the offer, and I'll take you up on it. I have one code on my truck; P0463. I'll give you the history of it, as it might help in diagnosis. It's a 2005 5.7 with manual transmission.

Almost to the day, my original fuel pump went out. I had it replaced at a mechanic shop two blocks from where it stopped running. Everything was fine for two or three months and then the gauge stopped working. I figured they installed the cheapest fuel module they could buy. As the truck otherwise runs well, I decided to run it for a while to get my money out of the repair.

Last weekend, I replaced the fuel module. After the pump primed, it started fine and otherwise is just like it was the day before I did it-reliable, but no functioning gauge. I did the cluster test and the fuel gauge sweeps, so I think I can rule that out. The idea that I got a crap fuel module is possible. I didn't test the sending unit before installing it. Yet I can't quite buy into the sender also being bad on this pump, also.

Putting the possible issue of a brand-new sending unit defective out of the box (we can come back to that, if needed), there's just wiring, I think. I have the wiring diagrams and as best I can make out, the two center wires on the fuel module harness are for the sending unit. One is BL/GN and the other is BL/RD, IIRC. The BL/GN should be the ground per the diagram.

I followed these wires back to a large connector on the frame directly below the firewall. I stripped half of the insulation on the BL/GN wire midway betwen that connector and the tank and made a temporary supplemental ground to the frame. Nothing changed.

Any ideas of what to look for would be appreciated. Thanks in advance.

EDIT: Wires are BL/GN (sensor ground) and BL/WT (sensor sender) per diagram.
 
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jotin

jotin

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Let me look at a wiring diagram today for that truck and I'll get bAck to you there's a possibility you'll need to trace the wires from the back at the pump up to the cluster to check for an open.


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jotin

jotin

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Looks like from the sender it goes to your PCM. Pin 2 and 3 are the db/dg wire Wich is the sensor ground. And then the db/wt is the sensor signal. Both leading to the PCM. The PCM then I believe sends the signal to the gauge. There is an inline connector c135 that the connections go through.
I believe that connector is under the cab near the drivers floor board. It's a big connector and I believe it's grey any who, you need to trace each wire, from the PCM to the level sensor and make sure the wiring is good. That will lead you in a different direction. Could be a sensor ground to the PCM open. Or the signal itself.


2d3833e0ff0778a150ce3bced2dc72b1.jpg


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Core-Lokt

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Thanks. I've got that page; 8W-30-3. By my interpretation, you confirm what I see-the sending wires don't go to the cluster. But if you search about 3G Ram fuel gauges, everyone says they do.

It looks to me the sender sensor runs in to the PCM on the BL/WT (pin 33?) in C3 and out (pin 37?) to C7 at the fuel pump relay.

I'm going to do some checking. If you could, please determine what wires go to the cluster. Thanks again!
 
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jotin

jotin

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The input to the cluster is just a bussed message more than likely from the PCM through the fcm to the cluster. There's no hard wired single input to the cluster.


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jotin

jotin

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No problem


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Hot Ducer

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Atlanta Ga
Ram Year
2003
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Hemi 5.7
If anyone ever needs diagnostic info I can get whatever needed. I'm a tech for dodge here in north Dallas.
I specialize in drivability, electrical and a/c.
Feel free to hit me up for stuff!


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Any chance you can tell me what these rogue connectors are? Neither are in use.

1.In the drivers footwell

uploadfromtaptalk1466539326769.jpg

3. Under the hood

uploadfromtaptalk1466539366470.jpg

2003 1500 QuadCab 5.7 4x4
 
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jotin

jotin

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I wanna say the first green connector would be for a neutral safety switch for a manual. And the other one under the hood may be related to trailer wiring.


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Core-Lokt

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I think you're right about the small connector. I knew it was C309, but I never could find a harness that corresponded to it. Because of the way the PDFs are, it's not intuitive where something related is. The harness would show up under some drivetrain or frame category.

I checked my truck and I do have a harness plugged in. On a related note, I found a couple of connectors about where the center stack would start (one is red). I researched and found those are for an AT, so they're empty on my truck.
 
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jotin

jotin

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Posts
428
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your mom
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2003
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Yeah the 03-05 or so diagnostics Aids for wiring are basically garbage lol


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