Fuel level gauge DIVE

[JARichard]

Well, went to get breakfast and had 1/4 of tank. All of a sudden the gauge NOSE dived all the way to the left. Resting on the little barb. I am fixing to go fill-up but I know by the miles I am no where close to empty. I recently installed the vent kit. But I marked everything and put back in exact same location. I also checked the voltage on the sending unit while I had it out. It was good. Do you guys think this is a fluke? Or am I about to spend some money. Gauge worked fine until now.

 

[Wiredawg]

I think there is a problem

I think you have a problem. The sending unit sends signal to PCM which converts to digital signal and sends to guage. The PCM has a delay built in to eliminate guage flux on hills etc... so you virtually will not so rapid rise or drop in reading. The primary way IMHO for gauge to abruptly drop is loss of power or signal.



This is concern I have when transferring fuel from my aux tank to my main tank: There is such a delay that it is easy to overfill. In fact, I have my two tanks vented to each other so if I accidently overfill, fuel actually goes back into aux tank.



Hope this helps,



Wiredawg

 

[tom sweeney]

wiredawg... . my gauge is acting screwy as well... . after 192k miles,it sits on empty,even though i KNOW there is PLENTY of fuel in the tank... . i ordered a sending unit from Moparparts for $51..... i'm hoping thats all it is... . i need this fixed BEFORE May Madness... . any help Ronnie would be appreciated... . take care Brotha-Man !!!

 

[Wiredawg]

Tommy:



Not absoutely sure about how DC made simple fuel gauge into a computer signal. Don't have my service amnual right now, but recommend following trouble shooting procedures. Did you have this problem prior to having connector corrosion problems? My thinking is the circuit uses small variations of voltages to pcm and is intolerant to problem circuits.



Let me know how this works.



I'm retiring Friday, so next time you hear from me, I'll have 30 years Air Force time under my belt.



Take care, Ronnie

 

[Turbo1Ton]

I have a similar issue to JARichard.



I recently installed the vent kit as well and now occasionally my fuel gauge will dive to the E, the low fuel indicator will light and it will ding. This is only momentary though because usually by the time I look down at it I have just enough time to see that is what it is before it jumps back up to normal. It didn't do this before the vent kit install so I am wondering what I might done during removal/replacement of the tank to cause this. I've got about 82k on the truck.



Jeff

 

[Spooled-up]

Here are some possibilities:



The in-tank module on the '03-early 05's is indexed on the tank solely by marks on the top of the unit and the tank itself. Here's a pic of the marks:



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There is a mark on the ring and the tank module marked with a green marker to indicate how much to thread the ring back on. In the picture above, the black arrow points to the green mark that was made on my ring and module. The red arrow points to the alignment mark that orients the module so that the float doesn't hit the side of the tank. This mark should be lined up with the three small marks pointed out by the white arrow.



What might be happening is the in-tank module was re-installed so that the float is hitting or rubbing the side of the tank. If you hit a bump in the road with low fuel, the float might get stuck on the side of the tank especially if the side of the tank isn't "bowed out" with the weight of the fuel.



If possible, try to get a pic of the marks with a digital camera to confirm that the in-tank module is lined up correctly.



Another possibility is corrosion on the electrical connector. If the gasket that surrounds the connector and makes a watertight seal is crushed or otherwise pinched or damaged, that could lead to corrosion.



The electrical connector can be removed from under the truck if you can stretch to reach it from the ground. You can also get to it from the side if you remove the wheel well liners (if equipped). The fender brace can also be removed if you need the room to get at the connector.

Just a reminder, to remove the connector, slide the red tab toward the rear of the truck and pinch the grey plastic release as you pull the connector off.



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These are just a couple of ideas. I'll keep thinkin' on it, but let me know if any of these work.