1966 Chevy Corvette gas gauge proubem

I put in a new sending unit in the gas tank. Now when i turn key on it goes to full and when i turn key off it goes to emty. My wireing is right my grounds are connected. My pink wire is to the 12V
and my brown wire is to key. Would my gauge be shorted or bad?
thank you
ned
nbgruver@embarqmail.com