[shenkerism]

Car is a 1980 Dasher.
https://youtu.be/IdIOTEnefLo
See video. My oil light and emergency brake light come on when my engine is over some particular RPM. I don't have a tach, but I'm guessing maybe 1500 or 2k.
Nothing at idle, and they stay on as high as I'm willing to take the engine. I have oil, no drips.
Due to the dependence on engine speed, I suspect the alternator is involved, but that's where my assumptions end. No other electronics are affected, even the other lights in the instrument panel.

 

[DbilasTDI]

that is only the oil light. Do you have a dual (hi/low) sensor setup? one sensor brown the other white? If so it could be the hi sensor brown I think.

 

[shenkerism]

Thanks for the input, uncertain how the oil pressure senders work, researching that now.
Things have definitely changed and new symptoms make me lean into the oil delivery system having trouble.

Now when the engine is cold the light will only just barely turn off if the engine speed drops quite low (still working on tuning the idle on a weber swap). Once the engine is hot the oil light behaves as it did before, switching off at low engine speed and holding strong at higher speeds.

I'm just spitballing, I'd love to know if I'm being a bonehead so here are my theories:

The engine is a swap from an 84 GTI into a Dasher. The oil-pickup and dipstick/tube are from the swapped-in block. Could they be incorrect for the application? Due to the positioning of the engine, the oil pan from the 1.6 had to be used. I haven't had an pan off and on a 1.8 in a while but it seemed like the pickup was pretty close to the bottom of the pan.
I have the old pickup, so I can compare it to others, though I won't have anything other than pictures to compare to.

Could the pickup tube be clogged just enough to allow only hot lower viscosity oil to be pumped through?

I'm going to be changing the oil this weekend to investigate more closely, and to know I'm refilling with the proper amount.

 

[shenkerism]

I have one sensor, the white, single terminal one.
My Bentley does not mention the dynamic oil pressure system, I have no buzzer, and the larger 2-terminal can is nowhere to be seen. The 1.6 oil filter flange was used and doesn't have any ports on it for a sensor.
The white sensor is installed into the back of the head. I'm using a MANN filter.
The engine is not exactly what you would call a low-mileage unit. The head isn't much better.

 

[shenkerism]

Well my oil definitely had some tiny metal in it. I guess it's just that time. Block was free, and it's been getting me around successfully for a while. Head was also a first-timers refresh.