The homely Consul is predecessor to this hot little number ;]
I wonder how hard it would have been to check and see what was making the light come on. Isn't it a pressure check, hook something up and see what it reads?
Sad. So many bad mechanics.
So it works like this, the long version.
There's an oil pressure galley, a passage that typically brings oil up to the top of the engine, to the hydraulic lifters and valvetrain, and this galley is plumbed for a sending unit that goes to either an "idiot light" or an electrical gauge, or to a mechanical gauge via a tube.
Sending units can also fail by way of leaking, sometimes spectacularly although they usually give you some warning by leaking a little, then a lot. I went to go look at a 60's Ford Fairlane one time that would leak out a quart in a minute via a defective sending unit. Simple fix, replace it.
Sooo, when the idiot light is on, or a gauge reads zero, there's a very good chance it's telling the truth, but you'd probably hear something wrong with the engine as well, noisier.
The way to correctly trouble shoot this is to unthread the "sender" in Bubba parlance, it's an 1/8" pipe thread, and thread in a hand held test gauge - easy to make - start engine, and see if the sender or gauge is lying or not.
Probably checking the oil isn't a bad idea, and neither is using good quality filters on your engine. Cheap filters plug easily, and don't have a bypass, meaning, not much oil pressure once they plug with crud from neglected engines running cheap oil that causes "sludge" in the engine, which is not pretty.
There is a way, with a T, to plumb a real gauge as well as keeping the idiot light, which is nice as an early warning, but I much prefer a real gauge.
A real gauge tells you so much more. Like how high the pressure is on cold mornings, oil filters can actually explode from too much pressure. Also how low does the pressure go at idle once the engine's hot.
Low oil pressure at idle indicates worn oil, or a worn engine.
You'll instantly have better pressure with fresh oil than you did with your old oil, especially hot at idle.
Pressure is created by resistance, like putting your thumb over the end of a garden hose, that's what creates pressure, not flow.
With tight main and rod bearings, you'll have good pressure. When these wear out, lots of oil gets by them, an unacceptable amount that throws excessive amounts of oil on the cylinder walls and can cause smoking, and of course the pressure is lowered.
Typically, you'd like to see 20 psi at idle hot, 40-60psi driving down the road.
The newly rebuilt 318 in one of my trucks gets 75psi cold, quite a bit, and it's comforting to see that. Hot oil pressure is 30psi, because the engine is "tight".
Don't ever buy a "high pressure/high flow oil pump" to help an old failing engine. High pressure can lead to smoking/carbon fouling or the combustion chambers that can lead to "hot spots" that cause pre-ignition, robs power and is a great way to melt a hole in the top of a piston, and high flow just means sucking all of the oil out of the pan faster, and without a larger capacity racing oil pan, a recipe for disaster.
With racing oil pans also come "windage trays" a tin sheet between the rotating crankshaft and the 4-5 quarts in the oil pan to reduce windage, the crank's ability to create a vortex inside the crankcase that keeps the oil in suspension around crankshaft, robbing horsepower and flinging lots of oil on the cylinder walls.
This is actually how Briggs & Stratton, Kohler and other small engines lube everything, via "splash" created by a "dipper" cast in the the rod cap to dip into the oil on intake and power strokes - in four stroke engines - and fling it on everything in lieu of a "full pressure" oiling system that oils main/rod bearings via drilled crank journals, passages to the cam bearings, etc.
While Chrysler was putting Hemi head engines in cars in the 1950's, Chevy's OHV 216 straight six engines still used a "splash" lube system without an oil pump, truly archaic.