I was running my bronco for about 15 minutes then parked in neutral to play around with new radio i installed and setting the presets on it. After about 10 minutes the engine shut down and it would not let me start it back up. I thought it may be an alternator but the next day it started up right away and no problem to the battery at all. I am no expert, but could this be a coil? Does the truck shut down when the coil gets too hot? Or am I looking at a different problem, radio draining too much juice maybe? I have the positive wire from the jvc stereo unit hooked up directly to battery is this a problem? And what is best way so this does not happen again.