The two lights, oil and battery sometimes green or red, need to check on your particular car.
VERY IMPORTANT.
The generator/alternator light will come on the instant you stop charging because the internals are bad or worse the belt broke(no cooloing,.....type 3 diff. story)
The oil sender switch will sense if you have 7lbs or less oil pressure and will come on.
Hot days and cornering will set the light on sometimes (flicker).
The idiot lights are more reliable than some more expensive gauges you can buy and hook up.