I own a 2002 Ram 1500 with the 5.9 360. My oil pressure bottomed out so I pushed it in the shop and put a new sending unit on it. Still no oil pressure so I spent the day dropping the oil pan and installing a new pump, new oil, new filter. Got it all back together. Still no oil pressure. I revved it up and it will go to normal pressure for a second then back to zero. I'm lost from here. Any suggestions?

 

put a direct reading gauge on it. Hind site, would have done that first before the pan. If your getting pressure you know the dash gauge is junk.