Holiday Rambler Motorhome not starting?

I’ll begin by saying that this is not a passenger vehicle like the choices I had say it is, it’s just I chose those cause there’s no other options for Holiday Rambler or Monaco or Cummins which is the motor that’s not starting. So, a little backstory about two weeks ago, maybe less than a week ago, I found that I had left the key in the ACC position, and I drained the battery. I tried the battery boost that’s available on the coach here, and it doesn’t seem to be functioning which points to a bad solenoid relay for it so I’ll be replacing that but I don’t think that’s causing the issue right now though it might be I tried to jumpstart it, and it started and it ran for a little and then I’m not sure if it’s sputtered but it just shut off. I tried that one more time noticed that it looked like the check engine light may come on is, so it’s Cummins diagnostic for it and I’m waiting for a Cummins scanner to come tomorrow so I can get some better perspective and what’s going on Warning light when running does come on the dash I’m not sure what that’s about. Check Engine light doesn’t stay on one thing I’m noticing is that there’s usually a wait to start indicator and I’m not seeing that on the dash either. So, I don’t know what that’s about either and low fuel light seems to flicker when you go to try to start it, and I’ve already run the gas coach generator to confirm that there is fuel. So, I’m trying to figure out why I won’t start now. It’s not the battery because I don’t know if I can attach a video of it here but in the video, it shows that the battery is well over 12. I checked the fuse for the ignition pierce to the OK I even swapped fuses Thinking maybe there’s something going on with the fuel sending unit that could be why it’s saying indicating that there might be a fuel issue and then again it may point to the Relay I mentioned which could affect starting the coach so your guess is as good as mine right now I’m hoping it’s nothing severe, and that it can be repaired soon as I get a chance, but I do appreciate any input on what’s going on here. Thanks