GM Delco Radio problem

I left the key in my truck ignition turned to the "on" over night and the battery went dead. After I charged the battery the display freq light stays in the on position after the truck is turned off and the key is removed. This has been killing my battery overnight. Does anyone have any ideas how to make the freq light go off other than pulling the fuse for the radio?
Thanks

What year and engine do you have?

does your radio turn off after you open the door? even the passenger door?
Does your dome light come on when you open the door?
It might be the switch in the door handle. The radio will shutoff automatically after 15 mins.