My low oil level light comes on in my 2001 Pontiac Grand Prix. It goes off if I shut off my car and then restart it. I replaced the level switch and it didn't help. I was told to replace the wiring harness as it gets oil on it when the filter is changed.

Now that I think about it you will need to replace the ignition switch. You should be able to use the old cylinder lock and key.

oil drains to pan then takes a few seconds to refill filter upon starting.
It takes a few hours to bleed down like overnight.

1. Check your oil level. If oil level is not ok, correct oil level and find out why oil level was low and correct the problem. (Leaks, bad PCV, Burning oil due to severe engine wear, nobody has bothered to check it for the last 3000 miles, WAY overdue for an oil change, etc.) If oil level is ok, proceed to next step.

2. Remove the oil pressure sensor and install a manual oil pressure gauge. Run engine to verify low oil pressure. If gauge shows that the oil pressure is low, overhaul or replace engine. If oil pressure is ok, replace oil pressure sending unit and retest.

If the engine is running well and not running hot, chances are that the coolant level sensor has failed. You can either replace it or ignore the warning light and just check the level as "routine maintenance"
while checking your oil and other fluids weekly as every good vehicle owner does and has done since there were cars to drive.

The oil level is probably too low, get an oil change, not only will they fill up your oil and change the filter, but if something is more seriously wrong they will bring it to your attention.
Plus an oil change is cheap insurance.

There are seperate resistors for the different speeds. No resistors means the fan runs on the highest speed. Sounds like the resitor pack is bad or there may be a wiring issue.

Because the driver info screen isn't working may mean a wiring problem. I have a similar problem in that my low oil level light comes on. I can get it to go off (after checking the oil level) by starting the car, shutting it off, then restarting it. I was told to replace the wiring harness after replacing the level switch didn't fix the problem.

change sensor in water tank

You should find it on the side of the oil pan.

Possibly very low on oil.

i presume that motor has a few miles on it. possibly the motor is so worn that it can't maintain a decent oil pressure. quick fix is to add heavier oil which hopefully will last for abit. be careful if you are in a cold climate as the thicker oil will make it harder to crank over in the winter.

Robert