On occasion, my truck won't start. Usually this happens after shutting it down, and then within 10-15 trying to start it again, such as at the gas station. When you turn the key, lights come on, etc, there's obviously electrical power, but the starter won't turn over. After about 10-15 minutes it starts fine. This isn't an every time problem. Is there a solenoid, etc that might be wearing out or getting hot and causing this?