Yesterday my '05 5.4L developed an intermittent "click" and no crank problem. After trying to start 6 or 7 times, it finally cranked and started. This morning the "click" no crank problem was back. In doing some voltage measurements while my wife turned the key to the start position, I found that both solenoid terminals had 12V. I then measured the wire going into the starter and it only had 300mV. I then disconnected the negative battery terminal, and removed the wire connector from the starter solenoid going into the starter. The solenoid terminal nut was not tight, and I could see arcing burns on the bottom side of the connector. I then cleaned the cable terminal, and the solenoid terminal with a wire brush, and tighten the nut. Problem fixed, no parts needed.