Doesn't anyone have a wiring diagram for the 1948 Olds 98? I badly need the circuit for the gas tank. I dropped the gas tank and the sending unit is okay. But nothing on the gauge.
Hope someone can give me some help.
Lee

 

I have to believe that the wiring for the gas gauge circuit on a ‘48 model car is as simple as it can get. Gauge wiring was simple on cars into the 70s and 80s. Just a single circuit. It should be easy enough to trace the wires from the sending unit forward and check everything to make sure there are no open circuits or shorts.

You say the sending unit is okay. How did you test it? Did you attach an ohmmeter and check the resistance through the sender’s full range of motion? What values of resistance did you get at each end of travel?

What does the gauge actually do when it is hooked up and you turn the ignition on? Move to E? Move to F? Do nothing? These sorts of things will help diagnose the problem. If the needle doesn’t move, did you check it to make sure it isn’t stuck?

I really don’t think you need a wiring diagram to tackle this. You just need to be systematic and check the circuit and components from one end of the car to the other.