Audio Systems: 1996 explorer, market radio, explorer xlt

Question
i have a 1996 explorer XLT with an after market radio in it i had it professinaly installed but the car has constant current going through it and is killing my battery do you what i can do to stop it from having constant current?

Answer
sounds like youre "professional" installation wasn't very professional.  I would definatly take it back to the guys that did it.  that shoudnt happen on ANY vehicle no matter what.  you shouldnt even have to worry about it since it's their fault they didn't do it right.