Fuel guage stuck!!

[97 z71]

K guys sorry, prolly isn't the right spot to post this, but after getting a new sending unit ans pump and wiring harness for the entire fuel system, about 2 weeks after I filled my truck up from half tank and now its stuck on full. After putting on about 25 miles it wouldn't budge, so I threw 10 bucks back in to see if moving liquid could free the float, nothing. After the truck sitting off over night for a while it would go down a little bit like usual, but starting it and it would slowly go right back to full. Any way I could figure this out? Iv put on about 60 miles since then and it hasn't budged, which I know isnt right. Any clues so I can do it myself? I really don't wanna bring it back to the shop and end up dropping the tank. Need help ASAP. Thanks for help in advance,

Luke

 

[shelbyt.67]

did u clean the ground when u replaced the sender? Also, I've had a couple of chevys that did this. It would read fully full until I got to a certain level, then drop like a rock. Usually around 2/3 a tank.

 

[outalne94z71]

check the ground wire, they read full if bad ground or if the sender wire to the gauge has no contact, if you ground the sender wire it should go empty

 

[97 z71]

By ground you guys mean the ground for the entire unit right? The one that's grounded to the frame behind or close to the filler hose correct?

 

[outalne94z71]

yes, also make sure the ground straps from the motor to frame are good too

 

[97 z71]

That could be it? I was lookin at them before the one I looked at in the passenger side under the cab, part of it was frayed but still in tact and holding, but that shouldn't matter cause it's just a ground right? But I'll check them later on prolly tomorrow after work, gonna be busy today

 

[outalne94z71]

the tail lights and fuel sender gets the ground from the frame, the frame is grounded through straps on the block which goes to the battery,with a bad ground the tailights are able to backfeed a ground from the front lights(when front lights are off) that are grounded to the fender but the tank sender cannot do that so it is dependent entirely on frame grounding

 

[97 z71]

Ah, but of the frame ground isn't good, that would cause the fuel pump to not get groused thus no power then right? Cause there's one ground for the sending unit and the pump

 

[tomh2012]

So did this issue ever get resolved? I am curious due to my fuel gauge doing the same thing? The only difference is that mine will either read full or empty no in-between.

 

[1993GMCSierra]

I always thought this was normal?

When I fill up, the needle goes a good 1/2" past the "full"mark, and takes about 65 miles or so before it moves period, then about 100 total before it starts to drop below the full mark. I wish it would actually stop on full, not sure if there is a way to adjust it or not.