loss of oil pressure

Hi everyone, newbie to these forums. Here's the problem, I've got a 1994, 5.0 van. when I first start it the oil pressure is at 50psi(cold start) after dropping off high idle it drops to about 32psi and about 10 minutes later drops to 0psi any throughs, oh yeah, no noise in motor at startup.

You must have a mechanical gauge, yes? Because the factory "gauge" is switch operated, it's not a pressure gauge at all. It reads either Zero, or about 40-45% full scale.

If you are referring to the factory gauge, replace the oil pressure switch.

Sorry, about not responding in a swift manner, was out of town for a couple days. Thank you for your input. is a oil pressure switch the same as an oil senting unit?, I disconnected the stock oil pressure gauge and connected a different one to get my readings. Thinking it might be the gauge. It's not.

No it's not the same exactly. A sender by definition is variable, a switch is not variable they are either on or off. The oil pressure switch is in the standard "sender" location by the oil filter as always. It's just no longer a real sender. Replace that, and your "gauge" should read correctly again.