Joe,
heh heh, we have two Joes posting in the same thread. Um, Joe in Cleveland,
I know you have way more experience with MV's than I do. However, the way you phrased your question made me think you had been drinking the dog water again. So I put the answer in very simple terms. I didn't mean to insult you. You just asked such a simple open ended question that read to me like you wanted to start basic in case you were missing something. Sorry.
Now that I know what you are looking for. You had a CUCV and lived with the "automatic" glow plug system and all its problems. You had a multifuel and its "push the button and start" diesel. I don't know which one you liked best, but I like to be the one deciding what is going in. That is why wiring in a simple manual control for the glow plugs seems best to me.
Something as simple as my posted above M715 starter button controlling the plugs directly. A M35A2 starter button turning on a glow plug relay would probably be better. I have never worked a HMMWV system, so I can't comment on them. However, if they have a position on the switch just for glow plugs. Then, you can wire it up as direct manual control of a relay or through some kind of timer. Again, I prefer the manual approach since you are starting from scratch.
Another option is the I think really cool timer switch Sermis used on his 6.2 M725. Police cars with gun racks in them have a timer on the lock of the gun rack. 8 seconds after you push the switch, it turns off by itself. That is just about a perfect time for a 6.2 with good glow plugs.
Better?