I have a 2000 tundra. When I turn the key to start the truck, the dash lights come on but nothing else happens, no sound, nothing, I have to turn the key several times before the ignition actually

When I turn the key, the dash lights come on but nothing else happens; no
sound, nothing.  I have to turn the key several times before the truck starts.  I've
replaced the ignition and the battery but the problem still exists.  It occurs
primarily in the morning. the dealership can't figure it out.  Any thoughts?