1998 115 eagle series, low oil light-tank is full

[walleyehed]

Have a sudden problem with an engine with system check, and the low-oil light comes on-no tone, just light on gauge. Shut engine down, restart, engine runs for 10-15 seconds and light comes on again, but no tone.
If I'm reading correctly, I should have a tone every 20-40 seconds, but don't....and yes, tank is full and has never been run much below half.
Any Good Ideas?
Thanks