I have a 2000 monte carlo with a 3.4 l engine. About a year ago I put another radio in it and when I went to start it, well it wouldnt start. I went through all of the motions, turning the lights off and on, didnt work. I then did the turn the ignition on for 20 minutes and it started right up. The security light was on and has been on ever since, however, the car never failed to start since. About a week ago, the battery went dead and I have not been able to get the car to start since. I have tried to leave the ignition on, etc. and I eventually replaced the entire ignition switch. I still cant seem to figure out what the problem is. I have heard mention of the bcm. Could it be this, and if so where is the bcm located. I would greatly appreciate any recommendations that might help me resolve this issue.