I have a 1997 f150 Lariat that has been giving me fits. Sometimes when I try to start it, there is nothing, but the door locks go up and down by themselves, but no start. I have replaced the starter,(3 times); the battery wiring (once) and the solenoid (twice) but every 3 or 4 days it won't start. If I let it sit over night or for 4-5 hrs, it starts. I'm stumped. Anyone else had a similar problem? thanks, Jon