Ok , lets hope that some one here can figure out THIS problem !!
For the most part I'm pretty good with my hands, but this is one problem that I can't seem to find any information on.
I just bought a 1948 Dodge D-25 4-door sedan, and the Fuel gauge is not working right. When I turn the key on the fuel gauge needle pins to the full side ( no the tank is not full of gas) so I figure that I must need a new fuel tank sending unit. So I bought one from "Roberts" and installed it. And it still did the same thing when I turn on the key, it just pins it's self to the full side. ( by the way, my old sending unit has one wire and the new one also has one wire) So I was thinking that maybe that wire that go's from the gauge to the sending unit is bad, so I bypassed it and ran a new wire from the back of the gauge to the top of the sending unit on the out side of the car just as a test, and still no good, the needle still pins to the full. Now my original gauge has two wires that come from the back of it, One that go's to the sending unit and is marked GA, which I'm guessing go's to the sending unit, and the other that is marked SW, and to best that I can tell go's to the ignition switch. When I turn the key on , my light tester shows that I have power to the SW side of the gauge, but nothing to the GA side. When I disconnect the wire from the back of the GA side or the gas tank sending unit, the needle go's to empty ( just like turning off the key). Ok, now I started thinking that my Fuel Gauge it self mite be bad, so I bought a NOS fuel for the 1948 Dodge, which by the way is identical in every way to my original gauge. So before I installed it I tried to hook it up from just jumping the hot side from my old gauge to the new and running a new wire form the back of the new gauge to the fuel tank sending unit, ( kind of like a test to make sure that that's the problem) But unfortunately I get the same result !!! The needle again (with the new gauge now) pins it self to the full side. Yes...I checked the ground to the sending unit to tank to battery and also checked it with gauge grounded an ungrounded, I even tried just running a new wire from the battery Hot side to the back of the gauge just to eliminate any internal wiring , and still the Fuel Gauge Needle pins to the full side. What am I doing wrong? I see no evidence that it was ever wired in any different way, And I can not find any up to date wiring diagram for this car that show just One wire from the sending unit. Can someone please solve this Problem ! Thank for reading
Dean Parker .... Phone 856-655-1830