My truck has made a howling noise for a few seconds after startup sporadically after shutdown since I bought it 12000miles ago. Then recently, I would turn the key sometimes and all I would hear is a click. After a try or two it would fire up. Tonight while my brother was moving the truck, he tried to shut it off and it started howling and wouldn't stop running. I ran out there and while I was trying to manually activate the shutdown solenoid, the solenoid smoked and it stopped. I took the solenoid off the truck, loosened the battery terminals, and started the truck. After it fired up, I went under the hood to shut it down. After it shut down the starter started cranking, so I took the positives off the batteries. The Key was in the on position, but the clutch was not pressed in, and it cranked anyway. Bad starter , solenoid, or ignition switch? These trucks are too much between the throttle cables, steering, ... ...