Check engine oil light

THe engine light is notifying you that the cpu has found sensors that are outside set parameters. Have the fault code s read and replace faulty unots.

Hi Nikki, What oil was low? Was it engine oil or gear box oil? Did the engine overheat? what exactly happened? Did you hear any strange noises when the engine stopped? Was the vehicle towed or was it on the back of a recovery vehicle? If it was towed, at what speed and over what distance? What engine is fitted? Is it petrol or diesel powered? Give as many details as possible to help us help you. Regards John

The new alternator is probably ok.
I would say you burned a fuseable link in the wiring harness.
The alternator has a fuse wire between it and the battery to protect it from overload.
Have someone check the wires coming out of the back of the alternator. The big wire should have battery voltage, the small wires energize the alternator when you start the engine.

the oil light can be from a bad oil sending unit or a faulty oil pump in the engine, i would have the pressure tested ASAP at a shop.
once the issue causing the codes that turn on the check engine light are fixed it should be reset by the mechanic that did the work.

Mystery oil. Find at advance auto, red and black can poor into engine oil

If it is a 3.8 engine change the crank sensor,they go bad on the 3.8 engines.

You need to determine where the oil is leaking from. Could be oil pan gasket or drain plug. Look for damage to the oil pan. The damage might be minor but bad enough that the pan won't seat tightly on the engine

Done cars have a kill switch if they are low on oil. Check your oil. If the oil is good, it may be the ignition switch.

no, it's not the transmission. No monitors for that. It sounds like your check engine light.
When your engine computer detects a problem with it's engine management controls, or when an emissions problem is detected, the computer will turn your check engine light and store a code or codes describing the problem.
Autozone will scan your codes for free. Then you'll know if the light means a major problem (fix right away) or a minor problem that needs attention. When it's fixed, the light will stay off.
You won't know what that light means until you get the codes read. Good luck.

I'm going to tell you what you don't want to hear. Once you run it out of oil or excessively low on oil to the point that it's knocking you likely (99%) have damaged the engine rod and main bearings as well as the oil pump (possibly other internal parts as well).
you could try using a good viscosity improver like lucas additive but generally it won't help with that kind of problem. Best option is a good engine from a scrapyard....expensive, but less than a rebuild.
Wish I could tell you to push a little red button somewhere and it will be fine but in reality, oil is like your blood...Run out of it and the engine is dead.