More than likely the wiring is there as GM probably only used 1 wiring harness back then for all the cutlasses.
Depends on what year Cutlass Supreme you're referring to...
If your battery was dead and you jumped it to get it started and the gauge shows your not charging you need to replace the alternator.
i have 1991cutlass supreme v6 my digtial gas gage stuck
Most likely either a bad float in the fuel tank or defective gauge
I believe it was 1966 and 67.
To reset the fuel gauge on a 1998 Oldsmobile Cutlass, first, ensure that the ignition is turned off. Then, disconnect the negative battery cable and wait for about 10-15 minutes before reconnecting it. This may reset the fuel gauge by clearing any faults in the system. If the gauge still does not function properly after this, it may require further diagnosis or repair.
If the gauge is reading hot and the car is running normal temperatures, the water temperature sensor needs replaced.
The cause of the faulty fuel gauge is probably the fuel gauge sending unit located inside the fuel tank. Replacing the sending unit would require dropping the fuel tank.
Check your cylinder pressure with a compression gauge. The gauge will hook up to your spark plug openings.
The color of the wire going to the fuel tank sending unit from the tank level instrument on the dash is taupe (or light tan). 1970 Olds Cutlass SX
The cost to fix the gas gauge on a 1997 Oldsmobile Cutlass Supreme can vary widely depending on the specific issue. If the problem is with the sending unit, repairs may range from $200 to $400, including parts and labor. If the issue is with the gauge itself or wiring, costs could be lower or higher. It's best to get a diagnostic from a mechanic for an accurate estimate.
To fix the gas gauge on a 1998 Olds Cutlass Supreme, first check the fuse related to the fuel gauge in the fuse box. If the fuse is intact, inspect the wiring and connections at the fuel sender unit located in the fuel tank, as these can corrode or become loose. If the wiring is fine, the issue may be with the fuel sender itself, which can be tested with a multimeter or replaced if faulty. Lastly, ensure the gauge on the dashboard is functioning by checking the instrument cluster connections.