HELP!! Fuel gauge on empty all the time. advice

[stang4u2nv]

hey fellas hope everyone is doing great as well as their stangs... to the issue at hand...i have a 1990 mustang gt and like the title states my fuel gauge reads on empty all the time. However the car does some weird things like, when the ignition is off the needle rises(not sure yet if is fuel level dependent or not. will check tonight when i put gas if when the ignition is off it reads somewhat to the level that i just put gas in)....anyhow today i replaced the OEM sending unit from 50resto.com and i installed it and nothing still reading empty with vehicle running. next step was to replace the fuel gauge from dash with another used unit and still no reading. so i decided to check the OHM readings and with the ignition off it reads about 39.xx ohms.....so i told my brother to open the ignition switch on and for a split second the ohms read somewhere around 83.xxx then 98.xx and then the signal dissappear...it is almost like the signal is there with ignition off and dissappears with the ignition on. I Read somewhere that this happened to someone else and it was a loose wire from behind the cluster....or maybe the chip inside the cluster(anitslosh) i am really at a loss and frustrated right now. i bought the car in this condition with the fuel level not working but i just don't know what else to do right now...can anyone help me out??? if it is the wire behind cluster which wire would this be?

 

[lutter94]

Where did you read the resistances at? The gauge? Try reading it at the sending unit and just start following the wires, maybe there is a broken wire somewhere along the way. It would be much easier to fix than something behind the gauge.....

 

[hndaklr]

Lol I read the title and it seemed pretty funny, my tank is on empty all the time, Its a mustang, something's never change

 

[hndaklr]

Hahah they pass everything BUT the gas station lol

 

[stang4u2nv]

the resistance i read it on the wires right before the sending unit enters the tank.....i guess there could be broken wires but i highly doubt it since the car is in pristine condition 48xxx miles and all....anyways i'll ground the yellow wire at the sending unit and see if the gauge reads full if not then remove cluster and tinker with it....any other ideas?

 

[stang4u2nv]

anybody?

 

[rz5.0]

Bad sending unit

 

[Raffaelli]

The sensor wire is shorted to power somewhere.

 

[Venomous96Cobra]

x2 Bad sending unit.

 

[lutter94]

Did anyone read it? He bought a new sending unit.....unless you guys think the new one is bad as well......

 

[rz5.0]

/\Guess not. Ground?