mcelroyx

I recently returned from vacation and my battery was to drained to start the car. After attepmting to charge, I removed battery and took to Autozone to charge and check battery. Battery checked fine so I installed and, of course, car starts fine. This morning I got into the car and as soon as I opened the door, I noticed that the radio was playing. I did not leave the radio on and I had removed the key anyway. Naturally, the batter was drained but it still started, very sluggishly. After a few start attempts, I got the "headlight monitor message take to workshop". I am perplexed why the radio would have stayed on after I turned the key off and removed from the car. I am researching battery drain issues on this forum but if anyone knows what might cause the radio to either come one or stay on then please speak up. Thanks for any input.