I have a 2003 ford explorer, and out of nowhere my low oil pressure light has come on and automatically shuts everything down. I've checked and the oil level is perfect, I've had no problems what so ever. The oil has been changed regularly at 3000 miles. I've had one person say oil pump and another say oil pressure switch. Not sure?

Check connections to oil pressure switch and then the switch itself.

Hello,
I had a similar problem with my 1967 Camaro; no oil pressue at idle.
Turns out it was the "cheap" oil pressure gauge.
I know, it's not computer controlled, however, I would say it could be a faulty oil pressure sending unit, or switch.
Who knows, there may even, and, probably IS a "low oil pressure" relay that could be faulty, thus causing everything to shut down.
Also, I would check the connection at the oil pressure sending unit/switch, and make sure its not loose.
"Worst" case could be a failed oil pump... (or possible clogged oil-pump pick-up screen, though unlikely if you bought new and changed oil regularly).
Just my humble opinion and previous gremlims...
Good Luck
Wayne

I agree with the 2 posts ahead of me.