Hello I'm doing a install for customer on a 2012 Chrysler 200. I was putting head unit in and there was spaghetti for wires behind head unit. There was plug to plug into stock harness. And it didn't have a accessory power only constant power but there was a red wire ran separate. So anyways deck does not shut off with car. Then she had to jump car. While Hood was open I saw a red wire coming from fuse box. I'm guessing it's ran off constant power. What is a good source to get 12v accessory power? Also does any one have good place to run 0 GA wire through firewall? Thank you
