Isx shutting down randomly

The shop only has a doner for a cm870 they have different connections. Have not been able to locate a doner.

 

Mobile repair Boise had said checking the ground from the frame to the block.so far I have not found a direct frame to block ground. I found frame to starter then starter to block. And frame to cab. There has to be one I would think. That may be a problem

 

I don’t know if this will mean anything. When I turn my key on the lift pump takes a few minutes to turn on. If you try starting it. It will just crank. There will be no power to the fuel shut off ( between the fuel timers and meters) when the lift pump kicks on there is power to the fuel shut off. When the truck dies it loses power to the fuel shut off.

 

Also ther is no power to the shut off

 

The dealer it was at just said it was the ecm was losing contact. They ran a new wire from the ecm to the circuit breaker. Said all was good as soon as it left the shop it was stalling again.

 

At this point I’m leaning towards a ecm but hoping it was a simpler fix.