Hello all here is my issue i have a 1990/91 corvette convertible and im replacing the whole stereo since i have removed the old head unit from the car the battery goes dead over night.I haven't had any previous problems and iv heard that some have had issues like this but didn't really absorb the info that i should have on this matter.Do i have to bypass something or is there an adapter for this or is it just bad timimg that this is happening.Any and all info is greatly appreciated.I have removed the Delco bose head unit and speakers completley from the car and i am replacing it with aftermarket head unit,speakers and wiring...thanks

I'm a little confused....do you already have the new stereo installed, and now the battery is dead overnight, or do you just have the original stereo out?
The Bose system has relays that can stick, or malfunction and drain the battery.

I have the original Bose stereo out and im wiring the new stereo but it isnt in yet.Once i pulled the old one out i noticed the battery went dead overnight and i started the car to let it run actualy took it on a 20min run to get some cold beverages and again in the morning it was dead again.My concern is if there is some sort of connection with the Bose system and maybe a circuitry loop beings the old system has its own CDm  that im not aware of.Any help on the matter is greatly appreciated.Im running a new double din kenwood ,focal speakers and all new wiring and prolly new alternator and battery but im hearing a clicking noise once the battery goes dead? Thanks again from BILLYDEE pictures to come eventually .

First of all thanks to all for the suggestions but the issue has been solved.I am by no means an electrical person at all BUt heres my opinion. When i first took the bose stereo out and unplugged the factory harness my battery went dead thefefore when i installed the aftermarket harness the circuitry loop went complete again and now the battery stays charged.I guess thats why they supply an aftermarket harness i know its crazy but hey it works.I guess chalk it up for the books and i didnt see it coming but im not complaining.Again thanks to all for the suggestions and chalk it up to experience guys ...have a good day and thanks