I have a 89 7.3l and my fuel guage works but neither one of the sending units in the tank works. Where is the ground for these sending units, I believe that since both tanks won't show fuel level in the dash that the grounds are corroded.

 

grounds are on the trim ring on the tank, and it goes to the frame or crossmember.

 

Thank you, I will try that within the next week or two and post my results.

 

My sending unit turned out to be bad