1977 Plymouth Volare Wagon w/318. This has been an issue since I bought the car, as it sat for over 20 years and many of the systems have deteriorated. When ignition is off the needle of the gauge comes to rest far in the corner of the "E". Switching the ignition on the needle bobs up slightly, but not by much. It always remains in the same position no matter how full the tank is. Early on I had to pull the dash to change the indicator lights. I inspected the gauge and noticed the needle had become dismounted from its inner workings. It was a very delicate operation, can't believe how fragile their insides are, but I managed to fit it back together and reinstall it properly. Yet the gauge still reads empty. I consulted my Haynes manual and decided to do an ohm test off the sending unit leads. I tested it with the tank empty and the tank full. Both readings were around 75 ohms. This indicates to me that the sending unit only gives an empty resistance reading no matter how full the tank is. Problem is, I went and pulled a similar sending unit from a 77 Dodge Diplomat with a 318. They both operate by the same concept, but are set up for different gas tank configurations. The diplomat had a top port gas tank sending unit, my wagons sending unit port is low, near the bottom of the tank and it faces forward toward the differential. All the connections were the same though so initially I tested it and it gave 75-80 ohms @ empty and 11 @ full. It appeared to work properly, so I hooked up the diplomat sending unit to my wagon, grounded it and propped the float up to the full postion, but the gauge still reads empty I also hooked up a test light to the guage wire and it would give an intermittent blip, don't know if that means anything. Tired of running out of gas without knowing when, lol. Its been impossible to adequately calculate the gas mileage with the carb in the state it is. I have to keep a gas can on me all the time. Anyone have experience repairing this system? Much obliged for your help, a Merry Christmas to everyone.