I have a 2003 Yukon I use for Rural Mail Delivery. It has about 300k miles on it and the transmission was rebuilt 2 and a half years ago. Recently, toward the end of my mail route, it starts to sputter out and wont restart unless you turn it off for several minutes and let it rest. I drive between mailboxes without putting it into park unless I have to exit the vehicle, so I'm taking a wild guess that its somethibg about the stop and go and constant shifting up and down between 1st, 2nd, 3rd gear, etc that is causing it to sputter out and die but I dont know much about this stuff. When this occurs, the battery light comes on like it did when it would sputter and die I had to replace the alternator, but this never happens unless I'm on my route. Is it overheating, maybe, or what?