"I haven't had a chance to go look at my Service Manual for MY93 but how can a faulty oil pressure switch affect the low oil light?"
When the light came up on my 92 Deville I ended up tracing the problem to a faulty oil pressure switch. It was a cheap and easy fix, so I figured he could start looking there. There was a pinhole leak in the switch that prevented the presssure from building properly and thusly throwing the light on. The hole was so small, barely any oil leaked out so it didnt affect the amount of oil in the engine... I looked at my service manual and realized I need to spend some time with it. I cannot find where you would diagnose the problem.