On my 1969 cutlas When key is off the gas gauge reads half tank when you turn key on it goes way past full any suggestions would be greatly appreciated

 

Gene, had a similar fuel gauge problem on my 67 Delta Custom. This thread helped me track down the problem. Worth checking out.

https://classicoldsmobile.com/forums...l-gauge-43247/

Turned out mine was a bad sender and, of course NLA. Other threads here pointed me to using one from a 71 Delta. Lots of good info and helpful Olds folks here.

Dave