Wait light stays on, crank but no start.

[Mogman]

Yes, next step will be to check voltage and then ohm out the plugs.
There is a IP diode that was destroyed, burnt and cut in half. Would this have anything to do with it?
What is this diode for?

The IP diode shunts reverse EMF to ground, if it is burned in two then it is no longer effective but is also not interfering with the operation of the IP.
Not all HMMWV's have this diode (as shown by the dotted lines) so it is not essential for operation.