I've got one coming back from a customer - runs for 20 minutes then throws an oil pressure light. Not sure if you learned anything from the above - I'm assuming it is the sender, highly unlikely a real oil pressure problem.
Could be the sender, but if that doesn't correct the problem a couple other possibilities (these not common but are possible):
1. Check oil filter & hardware is installed properly...don't want oil bypassing filter and showing low pressure.
2. Check oil pressure with a known good mechanical gauge. Connect via pipe tee at oil switch connection.
3. If pressure checks out good, you may have a drain-back issue where some trash is clogging gallery in the head & oil is not returning to the sump quick enough & the pump is sucking air. This will drop oil pressure & cause a low pressure fault & shutdown.
4. If pressure shows low with mechanical gauge, then more work is needed-check oil pump screen for blockage, oil pump gears & end clearances & last thing is main, rod & cam bearing clearances.
All said-I'd bank on a bad sender or a bad wiring connection or bad harness.