My 04 was doing something similar and it was the positive battery cable running from one side to the other. It runs under the engine (I believe) and and chaffed clean and exposed the wires.
Eubee congrats on getting that thing started and running!
I've enjoyed reading your posts as my 6.0 is at the mechanic now with very similar issues you had. Mine would start fine in the morning and by the afternoon (after heating up) would not start any more. Mechanic already replaced the...