Generator will not stay running

[GreenAcresMO]

2004 Crescendo with Guardian QuietPac 75D generator.

Generator will not stay running.

Intermittent in length it runs.

Sometimes it will only run for a few seconds, or a few minutes, or maybe 20 minutes.

Carries a load without issue.

Oil Pressure, High Temp or loss of 12V... Have not started to troubleshoot.

Wanted to through it out here to see if this is a common issue and would speed up my efforts.

Thanks in advance for your help.

KJ