Kirk, first I need to know if the buzzer is coming on and the light is
flashing or is the light staying on steady?  The light should only blink when
the rpms are  2000  or more.  If the light is blinking and the buzzer is
buzzing under this rpm then you are having a problem with your "L" board on
the rear of your instrument cluster.
The light should come on steady at low oil pressures under 2000 rpms.
Let me know what your situation is and I can help you troubleshoot this one
further.
Ken Wilford
Van-Again
John 3:16