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Discussion Starter #1
Hey all.

I have a 1996 K2500 6.5TD Suburban. Psyched about it. I've already learned a hell of a lot from this forum, GMT400, FSC and a host of vendors. I've already ordered tires/rims, PMD cooler and oil cooler/lines. Replaced faulty mechanical bits like power steering pump, etc. Installed a double-din kit and a bunch of other cosmetic stuff.

What's driving me nuts at this point is the fuel gauge. It reads accurately. However, any acelleration will cause the gauge to bounce around between E and around 5 o'clock wildly until I let off the pedal again. It even crashes into the needle of the gauge below it sometimes.

Any idea why?

Thanks.
 

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Bad ground is the most common cause of a gauge that will read past full.

Anytime an open circuit happens the gauge will swing widly up past full,this can happen from a sender resistor that is worn out and losing contact.

Repair the ground and/or a new sending unit is where I would start.
 

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Mine had been doing crazy things too. After replacing the sending unit, it was still acting up. Wound up tearing into the gauge cluster, and the gauge itself was worn to the point if you lightly touched it, it would just fall. Used eBay cluster fixed it up.
 

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Im expeirencing the same issues with my fuel gauge, also a 96 truck
 

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Same here lol, mine goes nuts, empty is actually a quarter of a tank, and full is past full. But eh if anyone steals ma truck they will think they have a 1/4 of a tank and BAM! then I drop in and ninja them outta the truck and re-take my property.... uh but yea, Fuel gauge on my '96 acts up too.....
 

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Mine did that. I worked the grounding point at the rear of the engine, next to the fuel filter. Solved the problem.
 

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Fuel gauge just reading inaccurately is probably a sending unit problem. Gauge bouncing all over the place with truck motion is probably wires losing power or ground. The purple wire with a white stripe is the power wire. Black is ground.

As mentioned, it COULD wind up being the gauge itself. But I'd check the more likely wires at the tank first. ~FH
 

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Having some oddball problems with mine as well, it read within the lines, but kinda bounces around, almost like it follows the oil press gauge on accell and decel hahah. Full was FULL on the gauge, but nothing like being down around 5 o'clock. It seems to never go more than 1/8th of a tank in it's random bouncing.

Might tinker on it today when I'm doing other stuff, someone said the ground was black, and the power was purp/white was power. There's a ground at the back of the engine near the FFM? Where is it exactly? I'd like to throw a wire brush on as many contacts as i can find to maintain a good steady reading.
 

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I think the ground is bolted on top of the motor towards the back under the tranny fill tube bracket.
 

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I have learned to just live with the bounce.
 

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Been Around A Few Motors.
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Mine Does the same,well sorta. It fills way past full and takes forever to come off. But when it does,daaaamn it goes as fast as the speedometer goes the other way.
So I cheat. I keep my 100g slip tank full.
 

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^hahaha, mine does the same, I've filled it once since I had it, got like 50000 miles till it dropped below F, followed by the 50 miles to E hahaha!
 

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My fuel gauge pegs out beyond full after a fill up but seems to regain its accuracy at and below the halfway mark. But I have calculated my MPG so many times I have a good rule-of-thumb I always use. Set the tripmeter to 0 every time I fill up and never let the tank go beyond 325 miles or the 1/4 tank mark, whichever occurs first. ~FH
 

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I have a '98 3500HD with two factory tanks. The rear tank was removed when I got the truck. No matter how much fuel is in the front tank, the gauge reads empty. When you first turn the key on, it reads a little over 1/4 full but then drops to empty.

Where should I start ??
 

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Whistle Pigs Are Cool
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The Suburban sat for over a week, the fuel level is below half. I started 'er up and the gauge needle was swinging from half full to 5 O'clock off the marks. Back and forth. Forth and back with no regularity. I will fill it up and let my back recover from crawling around a friends Sprinter for 4 hours looking for the drain. Like always, it comes down to the aftermarket trailer wiring hookups.
 

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I have a '98 3500HD with two factory tanks. The rear tank was removed when I got the truck. No matter how much fuel is in the front tank, the gauge reads empty. When you first turn the key on, it reads a little over 1/4 full but then drops to empty.

Where should I start ??
That is totally normal on an original 2 tank truck.

The reason is the fuel balance module,it controls the reading to the gauge and the rear LP.

To solve the problem if you don't intend to have a rear tank you need to remove the balance module and wire the LP and sending unit for the frt tank into the corresponding wires from the main harness.
http://www.dieselplace.com/forum/4013913-post8.html
 

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Grabowski gets a rap on the knuckles for bumping up a zombie thread... LOL! That question is 1 1/2 years old racer. But still a good answer that may live a useful life in the world of Google. ~FH
 

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Grabowski gets a rap on the knuckles for bumping up a zombie thread... LOL! That question is 1 1/2 years old racer. But still a good answer that may live a useful life in the world of Google. ~FH
:hehe: :hehe: :hehe:

The Suburban sat for over a week, the fuel level is below half. I started 'er up and the gauge needle was swinging from half full to 5 O'clock off the marks. Back and forth. Forth and back with no regularity. I will fill it up and let my back recover from crawling around a friends Sprinter for 4 hours looking for the drain. Like always, it comes down to the aftermarket trailer wiring hookups.
:smashfrea :smashfrea :smashfrea
 
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