Fuel Gauge Problem
Thread Starter
3rd Gear
Joined: Jun 2009
Posts: 3
Likes: 0
From: Hesperia CA
Fuel Gauge Problem
I have been refurbishing my ’78 and I am down to the last few items. The one that has me stump is the fuel gauge. It was working fine and then all of the sudden it went from a half tank to full…without visiting the gas station. I have replaced the circuit board, checked all wires, sending unit, fuses and even purchased a new fuel gauge, but it still pegs out past full. I have noticed that when I tighten up the 6 o’clock nut on the back of the gauge the reading moves from empty to past full. I must be missing something, but can not figure it out…any suggestions? 
Former Vendor
Joined: Aug 2006
Posts: 76,656
Likes: 1,851
From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
If the gauge is pegged to 3 o’clock you have one of a few things wrong.
Defective sending unit
Missing ground from sending unit
Ohms wire off sending unit
Break in wire between the sending unit and the dash unit.
If you go to the sending unit and check to see if the ohms wire is off. If it is not off, pull it off and ground it out to something. The gauge should go to empty when you do this.
If the gauge responds to you grounding it, then you probably have a sending unit issue. What could be a ground off the sender or a defective sender.
Willcox Inc.
Defective sending unit
Missing ground from sending unit
Ohms wire off sending unit
Break in wire between the sending unit and the dash unit.
If you go to the sending unit and check to see if the ohms wire is off. If it is not off, pull it off and ground it out to something. The gauge should go to empty when you do this.
If the gauge responds to you grounding it, then you probably have a sending unit issue. What could be a ground off the sender or a defective sender.
Willcox Inc.
