Radio on anytime, I had a problem Options

[pepsiman]

I been thinking about it for a while now, and i had the idea of being able to listen to the radio and have my drivers side door open without the warning going off. (this would be really nice when cleaning the inside of the car) So i put a switch between the acc and constant wire on my aftermarket radio harness. I flipped it and blew my fuse instantly. What did i do wrong, i didnt have any exposed wire. I am giving up on this, and im going to try and just take care of the offending door switch, making my own switch to turn the warning tone on and off, i still want it to work in everyday driving (it has saved me from locking in my keys a couple times)