Fuel gauge always full

[MarylandGuy]

hello all, i have a 97 k1500 with the 4.3, fuel gauge always reads full. Fuel pump has been replaced with a delphi fg0086 unit less than 500 miles ago. Checked ground at the tank with a multimeter and that tested good. Cleaned it up anyway, no change. Any ideas? My next thought would be a short somewhere.

Last fill up it only went to 1/2 tank. Then randomly started reading full a few days ago and hasnt moved since. Driven approx 70 miles since it started reading full.

It’s not past the full mark, just right at it, when the truck is off it reads 3/4. all my other gauges work correctly. Seemed to be working under 1/2 tank but just this past weekend was the first time i’ve filled it completely.

I’ve read you need to order pumps by the vin in these trucks, which i did through napas website, possible i ended up with the wrong one?

Thanks for any help!

 

[c1500deathtrap]

You have a never ending gas tank. Obviously. Whats the problem?

 

[MarylandGuy]

Would’nt that be nice! The gauge is stuck on full. Obviously, these trucks arent teslas, should be seeing movement in the gauge after 70+ miles.

 

[df2x4]

Would’nt that be nice! The gauge is stuck on full. Obviously, these trucks arent teslas, should be seeing movement in the gauge after 70+ miles.

Depends on the truck and tank size. My '97 Suburban has the 42 gallon tank, I have to drive around 70-80 miles after filling up before I see the gauge move off of full.

It does sound like you have an issue, though. I'd suspect either the sending unit with the pump or a wiring issue.

 

[MarylandGuy]

Almost 150 now and still no movement from full. Truck is a single cab long bed with what i assume is the 34 gal tank. I will start looking for shorts in the wiring tomorrow.

 

[98 Nitro]

I recently have had the exact same problem. I tried the grounds too, did nothing. It started with the fuel gauge dancing around in park but was ok otherwise, then after a week always read half full and after I filled it up it always reads full. Guess when fuel pump inevitably goes out it will get fixed.

 

[Schurkey]

The fuel gauge has to ground through the sending unit to register properly. Any excess resistance in the wiring pushes the gauge needle towards "Full". You could get excess resistance from corroded wiring, or more likely from corroded connections in the harness under the vehicle. This resistance can be between the gauge and sending unit, or between the sending unit and ground--or both. My truck has a 4-wire fuel pump hanger: Fuel pump + and -, sending unit + and -. TWO ground wires.

When my truck had a BROKEN wire for the fuel gauge, the needle went past Full and stayed there until I spliced in a length of fresh wire along the frame rail under the driver's seat.. That was more than 20 years ago.

Alternately, the sending unit float could be stuck "up". Not real likely--but possible.

 

[c1500deathtrap]

Would’nt that be nice! The gauge is stuck on full. Obviously, these trucks arent teslas, should be seeing movement in the gauge after 70+ miles.

Speaking of electric trucks....https://media.chevrolet.com/media/u...ges/news/us/en/2018/oct/sema/1029-e-copo.html Scroll down to electric crate motors.

 

[Schurkey]

“It also represents our goal of a world with zero emissions, with the next generation of engineers and scientists who will help us get there.”

Bunch no-ethics lying dirtbags. You'd think they were politicians. Oh--wait! They take their cues from no-ethics lying dirtbag politicians AND no-brains lying dirtbag "Progressives".

Clearly, this country needs to clean house.

 

[c1500deathtrap]

Bunch no-ethics lying dirtbags. You'd think they were politicians. Oh--wait! They take their cues from no-ethics lying dirtbag politicians AND no-brains lying dirtbag "Progressives".

Clearly, this country needs to clean house.

Calm down, i just thought a drag truck with a bed full of batteries would be fun.