fuel gauge ground

[HDM]

Hello, HDM here. I am new and need some help.
Problem, Installing a replacement fuel gauge ground. I have the power to the Bat stud. I have the sending unit to the S stud. I have the ground on the gauge, grounded to the dash frame.. Now whereas the weird problem starts. when I ground the sending unit it will peg the needle on the gauge. no matter where or how I ground it it pegs the needle. BUT IF I GROUND THE SENDING UNIT WITH MY 12 VOLT TEST LIGHT THE GAUGE WORKS FINE. I have tried different places to ground and different wire etc. Help!!!!

 

[Alec_t]

Welcome to EP!
Are you sure the sender unit has the right resistance for the gauge you're using? Sounds like the gauge might be intended to work with a higher-resistance sender.

 

[kellys_eye]

Is the sender working correctly?

Darn - beaten to it....

 

[Bluejets]

Hello, HDM here. I am new and need some help.
Problem, Installing a replacement fuel gauge ground. I have the power to the Bat stud. I have the sending unit to the S stud. I have the ground on the gauge, grounded to the dash frame.. Now whereas the weird problem starts. when I ground the sending unit it will peg the needle on the gauge. no matter where or how I ground it it pegs the needle. BUT IF I GROUND THE SENDING UNIT WITH MY 12 VOLT TEST LIGHT THE GAUGE WORKS FINE. I have tried different places to ground and different wire etc. Help!!!!

There is no ground on the guage itself (except maybe for an illuminating lamp)
The gauge is fed with a regulated supply and a single line gets the "ground" return through the sender in the tank.

 

[Alec_t]

Can you post a link to the gauge datasheet/spec/image?

 

[pepi]

The gauge and sender must match.. example GM requires a 90ohm sending unit, Ford requires 180 ohm sending unit.

Are you sure what you think is a ground connection for the gauge, isn't really the connection for the gauge light?

Only 3 connections on the gauge, battery power, gauge light and the sending unit. Sending unit has one, connected from the S terminal on the back of the gauge The sending unit gets its ground from the tank mounting screws.

You would only need to add a ground wire from the sending unit. IF the tank is made of poly or is supported with steel bands that have a rubber insulation between the bands and tank.



Greg