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Discussion Starter #1
Hi everyone,

Oil pressure light that comes on (stays on red) when the ignition is on and the car is turned on.

If I switch the car off and on again - the light does not come back on.

The needle works great even when the red light is on ...

Your opinion on why it lights up?

Thank
1677125
you,
 

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The signal for the needle comes from a different sensor than the red light. It is possible the low pressure sensor sender is bad. Or you have low oil pressure.

I can't speak for your car, but I trust that light significantly more than the needle, which has wildly different reading depending on how hot the car is.
 

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Discussion Starter #3
The signal for the needle comes from a different sensor than the red light. It is possible the low pressure sensor sender is bad. Or you have low oil pressure.

I can't speak for your car, but I trust that light significantly more than the needle, which has wildly different reading depending on how hot the car is.
Thank you for your comment. but what is weird and funny is that if I switch on the ignition without starting the car the light remains on. then I cut and redo to start it the light turns on and off.
 

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It seems possible that could be caused by everything from a faulty sender itself (things fail in weird ways), or a wire that's slightly shorted that moves when you crank the engine, or expands with a small amount of heat and completes the circuit.

I also don't really know the expected behavior of that light when ignition on but engine not cranked. Maybe it's supposed to be on? The ARC does a little check circuit, is it like that?
 

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Okay, I'm going from memory here, but I'm pretty sure there's something unusual with the way that light is supposed to work. It's not just a simple direct connection to the switch, it goes through the ARC. It's also wired into the bulb check circuit of the ARC.

Again, going from memory, but IIRC when you first turn on the key it's not supposed to come on (even though the switch is closed due to no oil pressure) but then once you start the car it'll come on if the switch closes again. Something like that, anyway. It's definitely not "switch closed light on, switch open light off", there's some logic involved, probably in the ARC. But my Milano is long gone so I can't test for you.

My guess would be you've either got a screwy pressure switch or a screwy ARC computer (the one at the glovebox).
 

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Discussion Starter #6
What's weird is that it does it once. when the car has not started. then it doesn't do it anymore

I need to test again for validate that...
 

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Best way to check pressure is manual gauge to provide comfort that engine is good. If the dash pressure gauge behaves normally (consistent relative range cold and hot), make peace with that. gtv6 don’t have a pressure light just the gauge, one less thing to worry about. I’ll dig up my shop manual and see what it says about the ARC circuit, sorry am in the middle of moving.
 

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Quick and easy, try removing and cleaning the spade connection at the sender. See if that helps.
 

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Perhaps when you crank your car and have low oil pressure it wont send back message to turn the light off
 
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