07 HPDI 225 won't start

[MoeDaddy]

I had a tournament tonight and when I got back to the ramp I couldn't get my engine started. I even tried to jump it off my tm batteries and had no luck. During the tournament...about three hours in...I noticed the engine was getting difficult to start and I even knocked out my electronics a couple of times when I turned the ignition. When I got home I checked my batteries (I have two run in parallel for the cranking battery because I have too much stuff hooked to the cranking battery) and they are good. I'm gonna take it to the shop next week but, in the meantime, does anyone know what I may be up against??

Thanks in advance for your responses!

[FishWhisperer.]

Is it dropping below 9 or 10 volts. If you dont have enough battery voltage the motor may turn over but not activate ignition system. How's your grounds?