OK hears the deal, I started my M923 yesterday the oil pressure gage worked fine read close to 30 psi when warming up and works fine when driving. Today I started truck I noticed no pressure at all. I shut the truck off let it sit for a hour checked the oil, right up to the mark so I started it again no dice nothing. I'm surching therw the archives now and trouble shooting to. Could it be a sending unit or could it be electrical? I'll keep searching till I find out whats the deal. Sorry just a new guy to this lol