recently bought this 98 ta ws6 and owner failed to inform me that the gas gauge always shows full got stranded on the highway first time i took this car out any ideas why it always shows full? i wouldnt think its the sending unit otherwise it would show empty

 

UPDATE:

I bought this guys trans am - and HE failed to inform me the gas gauge didn't work.

Funny how he expected that courtesy but didn't provide it to me.