I was doing a tire rotation this past weekend and decided to check for seized front calipers on the front of the car. While the car was in the air, I left the key in the ON position in order to switch the transmission into neutral to let the front wheels spin feely. After leaving the key in the ON position for 1 hour, a clicking noise started from under neath the hood. I than remembered that the key was left in the ON position and quickly took the key out, after which the noise went away. For the entire weekend, I did not drive or start the car after this happened as I used our other car. Yesterday, the car did not want to start in the morning. I jump started and all is fine. Did the 1 hr. in the ON position drain the entire battery and thus for the noise under the hood? Does this mean my battery is getting old if it was drained entirely in 1 hr. from just leaving the key in the ON position? What exactly is working in the vehicle when the key is in this position? I assume everything is working including the fuel pump and every where else current is flowing into?