Fuel gauge issue

[NoVA_87_GN]

I have the dreaded fuel gauge issue. Been reading up on some of the other threads for tips to troubleshoot it but can’t seem to get anywhere. Issue is my fuel gauge reads empty all the time, even after I fill it up. I disconnected the sender at the rear bumper and the gauge pegged all the way past full. Reconnected it and it went back to empty. Tried to ground out the wire back to the gauge to see if it would swing the other way, but no luck. There seems to be a fuel pump and a bunch of connections ands hot wire kit installed. this is my first go around with the electrical on the gn, so go easy on the new guy. Appreciate any help I can get.

 

[TexasT]

Probably in the sender itself. Dropping the tank is in your future if you want it to work. I'd have a new or at least known good hanger to swap in.

 

[NoVA_87_GN]

@TexasT thanks for the reply. Is there a specific hanger I should look at getting or would one from local auto parts store work? Also, with wiring, it seems there are two wires coming from the sender, I'm assuming one is power and one is ground correct? There also appears to be a second ground that's screwed in to the underside of the trunk, do i need this second ground and is that a good location for it?

 

[TexasT]

Your dash will determine what you need. Analog I think is 90 ohm and the digital dash is different. It is a little strip resistor that the float moves over to generate the signal. If it gets corroded or damaged it is erratic or stops like yours did. You can use a meter when you get it out to measure the signal as you move the float.
While it is out I would replace the pump and wiring and the connector tube/hose from pump to hanger. Make sure that piece is good for submersion or it gets eaten up by the alcohol in the gas

 

[salvageV6]

You can test the dash gauge itself by unplugging the connector, leaving it unplugged, and putting a 100 ohm resistor between the black ground wire and the pink sender wire that goes back to the dash, it should go to full if the wiring/dash are ok. Actually the resistor will need to be grounded on the black wire end with the connector unplugged so that would be a 100 ohm resistor touching the pink wire and the other end to any good metal ground on the car.
Otherwise what was said above is spot on, I'm not sure who makes a good replacement sending unit however.
It's not crucial to use the 120 ohm sender in a digital dash car but the first 1/4 from full will be a bit off on the readings then it will drop normally at the low end. Sometimes you can fix the sender by cleaning and bending the tab that hits the resistor element and sometimes you can't because it's cracked broken or the tab contact is shot.
You may need a new O ring for the sender mount and probably new rubber lines out the 3 pipes on top of it for the feed, vent and return lines. Those are readily available from vendors.