Faulty gas gauge

2002 DODGE RAM
120,000 MILES • 5.9L • V8 • 4WD • AUTOMATIC
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MLS69
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The problem started when the truck shut off while driving through a parking lot. It restarted immediately. Next day, fuel gauge showed empty and would not start. No warning lights or sounds. Fuel pump, spark plugs and wires, ASD relay, distributor cap was changed. Gas hand will sometimes show half a tank and the truck will run for a few minutes. Then gas gauge drops back to empty and truck shuts off again. Computer changed a couple years ago as well. Have any more suggestions? Please help!
Aug 30, 2018 at 9:51 AM
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STRAILER
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Hello,

This sounds like it can be one of two problems. First there is a battery temperature sensor that can be shorting out causing the PCM to shut down along with the gauge operation or the PCM is going out again and if so I would replace the alternator because if one of the diodes is leaking it will take out the computer.

Here is a wiring test guide so you can see how the engine wiring goes and how the system works:

https://www.2carpros.com/articles/how-to-check-wiring

Check out the diagrams (below). Please let us know what you find.

Cheers, Ken
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Aug 31, 2018 at 1:47 PM
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MLS69
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I am certainly grateful for any suggestions. I will let you know what I find out! Thank you for your time.
Aug 31, 2018 at 8:44 PM
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STRAILER
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Please let us know what you find. We are interested to see what it is.
Sep 1, 2018 at 11:08 AM
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MLS69
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The truck is actually in a garage at the moment. It has been there almost two months. Nobody seems to know what it is yet. I will write back whenever I get an answer or need more advice. Thanks again.
Sep 1, 2018 at 8:46 PM
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STRAILER
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Okay, please let us know. :)
Sep 3, 2018 at 12:41 PM
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MLS69
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Hello Ken,

It has been quite a while since I messaged you for advice. My truck was in the shop for almost four months. Then I moved it to another shop when they gave up. It turned out to be the computer and the ignition coil. Finally, I have my truck back! My husband is going to replace the alternator as well like you suggested. Thanks again for your help.

Michelle S.
Nov 18, 2018 at 9:28 PM
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STRAILER
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Thanks for getting back to us. Glad you could get it fixed, that kind of problem can be tough. Please use 2CarPros anytime we are here to help.

Cheers, Ken
Nov 19, 2018 at 11:51 AM
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MLS69
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Thanks again. I will keep your email in my favorites file.
Nov 19, 2018 at 3:33 PM
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CASPARKS
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Ignition will crank but will not start. Cannot see a gas leak.
Nov 20, 2018 at 9:52 AM (Merged)
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HMAC300
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try resetting security system if that doesn't work scan for codes and check fuel pressure with a gauge autoparts rent it.
Nov 20, 2018 at 9:52 AM (Merged)
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SONKSEN3
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2001 Dodge Ram2500 Diesel. When Fuel gauge reads 3/4 , tank is at 1/4.
Nov 20, 2018 at 9:52 AM (Merged)
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ERNEST CLARK
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Check the sending unit in the gas tank, wiring, connectors and grounds.
Nov 20, 2018 at 9:52 AM (Merged)
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MAJORMAUS
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Cummins
Fuel 1/2 tank
Reading empty on analog gauge, fuel tank empty light on and digital DTE gauge showing zero.
Truck runs and starts fine. Ideas?
Thanks
Nov 20, 2018 at 9:52 AM (Merged)
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JACOBANDNICKOLAS
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Chances are the rheostat is bad on the float unit. The bad part, it is part of the fuel pump assembly and in the tank.
Nov 20, 2018 at 9:52 AM (Merged)