Many thanks from THE GREAT WHITE NORTH
After many hours of hair pulling frustration I located several loose and corroded grounds in the engine compartment. She runs like a jem now..

Sounds like a bad ground to me. The light flickering is probably just a voltage back feed. I would pull off all grounds from engine and frame, clean and reinstall and find the wire harness grounding points and do the same. Also check fuse panel connections. I have seen paint overspray interfere with good grounding points and since that machine is not that old one may have been left a little loose from the factory and now it's backed off from vibration.

The hyster is a Mod# H100XM Ser# L005V04733C.
The machine operates for approx 30 min to an hour and the lite starts to flash after 2 min of operation. The engine shuts down completely like turning the key off and will not restart for 10 min or so ( it will not even crank over) but I still have all electrical power for options. It has only done this to me once which makes it very difficult to diag but the operator says it happens constantly.
Thanks for any info

Ive seen those engines with 20 to 30 thousand hours on them with no internal work done with the proper care. The heads not the problem.

Need more details on problem how long does it run before shut down, what serial # is the machine, how does it shut down (spit and sputter or like turning the key off). Please give as much detail as possible.