I have a intermentant start problem on my 2000 5.4 Sometimes it will not start nor will the radio work. I can start it by crossing over the starter Relay. I have replaced the relay in the fuse box I did check and I was unable to find one on the relay box on the drivers side fender. I have also replaced the start relay on the firewall that is connected to the battery. I have also replaced the Ignition switch. I have noticed that when the key goes to start I am unable to get a voltage at the remote wire from the ignition switch, at the relay. Hope someone can help with this problem.

 

Carefully check the cable that connects to the starter. These are known to corrode and cause all sorts of problems.