Fuel Gauge needle stuck above full

Ok, see thread below for other related work that I have had done at Pep Boys.

http://www.automotiveforums.com/vbulletin/showthread.php?p=4504602&posted=1#post4504602

Now 3 days after this above work was done, I noticed my fuel gauge is still above full. I had a full tank at the time of the service, but, it hasn't budged at all from it's position and I've driven a good 50 miles since. Before the service, I would have seen the needle move after 50 miles. I'm going to give it a couple more days, but it doesn't look good. Looking at my Haynes manual with my beginner's knowledge, it looks like they may not have properly grounded the fuel level sending unit.

Any thoughts?

I'll keep you updated in a couple of days, and then back to the Pep Boys if the problem persists.

I'd be heading back there. Grounding is less of an issue than the electrical connector and the sensorfloat mechanism itself.

I answered this in your fuel pump replacement thread.
Your gauge power connector most likely isn't connected, broken wire,or bent level sensor rod when the pump was put in the tank.
Take it back to Pep boys, they screwed it up again.

Oh boy, so this is going to be the third time they are going to be going through the tedious process of syphoning out the gas tank, etc., etc.

And my third weekend with no vehicle. They should provide a rental car for these situations, but not in the warranty.

Ok, so my truck is back at the Pep Boys now. I dropped it off for the Early Bird service and just called at 8AM when they open. They haven't looked at it yet, but the guy I talked to at the Pep Boys says that since the gauge is stuck on full, not empty, that the gauge power connector is connected, and it most likely not related to the work that they just did. Sounds like he is trying to get more money out of me, by saying it is not related to the previous work, so not covered by the warranty.

Any ammunition I can use for when I hear from him again?

Ok, so my truck is back at the Pep Boys now. I dropped it off for the Early Bird service and just called at 8AM when they open. They haven't looked at it yet, but the guy I talked to at the Pep Boys says that since the gauge is stuck on full, not empty, that the gauge power connector is connected, and it most likely not related to the work that they just did. Sounds like he is trying to get more money out of me, by saying it is not related to the previous work, so not covered by the warranty.

Any ammunition I can use for when I hear from him again?

The gauge is past the full mark because there is NO power to the sending unit.
The sending unit is a potentiometer that adjusts the resistance to the ohmmeter (fuel gauge). as the lever on the pot goes down (fuel level decreases), the resistance goes up, causing the gauge to go down.

So lets say for instance, with a full tank, the resistance is 0 (zero), so the gauge shows full. At half a tank, the resistance is 50 ohms, at empty, the resistance is 100 ohms.

The guy at Pep Boys needs to study his gauge theory of operation. Apparently, he's not to keen on the basics of electricity.

I've had this happen to me twice when I replaced the pump on my daughter's '96 Sunfire, so I know for certain you have no power to the switch. Where the break in power is I can't say for certain, but with the tank recently being removed, A big RED flag goes up pointing to the installation of the pump.

Read about it here, it's good for a laugh;
http://www.automotiveforums.com/vbulletin/showthread.php?t=611302

Good luck.

I remember that post...it was kinda amusing to see I'm not the only one.
Yup, you're definately an authority after that experience:iceslolan

OK, got the truck back from Pep Boys on Friday, the needle was on half when I pulled out. I went and filled up on Sunday, and have driven 40 miles since. Guess what, the needle is sticking above full again. Surprise, surprise!! I'm guessing that when I told them what the problem likely was (from your advice), they just ignored it and did thier own thing. I'm going to let it go for a few more days until I hit 100 miles to be sure that it is not stuck. I'm contacting corporate Pep Boys soon. Just goes to show you that if you want something done right, do it yourself. I'll update you all again later in the week.