Fuel guage ALWAYS reads FULL***
 

Hey I got issuess...I replaced fuel pump and the fuel guage began reading full alll the time. Even with the car off. I had to replace the fuel pump anyway so I figured a new fuel level sending unit would take care of the problem. Still there. Still reads full. Car off, car on no matter what. Chased the wires with volt tester. All good up to the instrument cluster. I figured it might just be stuck since it doesnt move at all even with car off. Did that with a lil wire and as soon as I turn the truck on it goes right back to full. Iv read that this happens to A LOT of Gm products. Any ideas? Most people seem to have a fluctuating fuel guage or doesnt read right. I can work with it but it sure is a pain the ass and definelty effects resale. There are 2 grounds on the sender unit. I swapped those to see if anythign changed...nada. I dont know what to think or where to start. Just doesnt make sense. please help fellas.

Everytime I always had that happen its a ground. Unless the float is stuck up somehow in the tank

thats what I was thinking. Appreciate it brother. The float is definetly good so its gotta b a ground.

Usually though when the ground isn't connected the gauge reads way past full. If your able to get at the wires maybe try running a ground straight from the battery to see if you can get to work

yeah exactly its reading way past full. Where it actually reads full thats where the needle is. It shouldbe something simple. Most peoples fluctuate so i guess i should keep it optimistic.

What brand of fuel pump did you buy? I had an Airtex on mine and it was super noisy and if you filled up the truck it read past full for about 225 miles or so then would drop to empty.. That will scare you when your out in the middle of nowhere at 4am. I replaced it with a AC Delco one and now my gauge reads like its supposed to.. I still have the slosh swing but its livable and fairly accurate too.

Well the one in it from the dealer was the airtex. I replaced that with a piece of **** one from ebay for 100. So the new one I just bought is also an airtex from autozone. I think it definetly is a ground because it doesnt move whats so ever! haha But i hear u one the scary part. Im getting ready to head from arizona to massachusetts.

00 blazer 2 door 2wd,Mine went at 135K but i do all maintnance lil b4 the recomended time,fuel filter 10K,do it every 3rd oil change at 9K real easy,and every 3rd change run a tank of 89 OC with lucas,THAT SEAFOAM CRAPIS A FRUAD,AND I PROVED IT,IT MADE ALL THE ETHANOL(WATER FOR U NOT KNOWERS OUT THERE)DROP TO THE BOTTOM OF THE CONTAINER IN UNDER 2 MINUTES SO ITS JUST MAKEN U SUCK THE WATER THREW YOUR MOTR OF THE BACK,ADDITIVES SUPSE MAKE WATER LIGHTER SO IT VENTS OUT THE TOP OR MAJORITY OF IT) ANYWAYS GOT A NEW AFTERMARKET 169.00 FROM PLACE I GET PARTS FROM SINCE I WAS 12,at 6months left me stranded,they gave me another one,at 4 days shy same thing,they wouldnt do a refund only swap out,so went to autozone got an airtex and got 294K now on it,All 17 s10 n blazers ive owned,IF THE FUEL PUMP WASNT LOAD IT WAS ALMOST DEAD,NOT THE OTHER WAY AROUND.

oh and every ac delco or delphi i have put in my brothers truck or his buddys,i went thru 4 on the 1 and 7 on the other before they made it a year.

To isolate the fuel gauge problem, disconnect the electrical connector at the fuel pump end and put a 50 ohm or so resistor across the fuel level sensor contacts, turn key to ON and see if the gauge moves to somewhere between F and E.

This should tell you if the problem is in the wiring and instrument cluster of the fuel sensor in the tank.

Sorry but I do not know which wire colors to go across as I do not have a wiring diargram, perhaps someone who does can provide the colors.