Your dimmer switch may have been adjusted to the lowest setting.
That would happen if the alternator is over or under charging.
The only light that could come on would be the check engine light.
when my dodge stratus started to do that it was because I needed transmission fluid.
It would be very rare for a P1684 code to turn the light on.
you fix whatever is making it come on :-)
It might be that your pcv valve is plugged or the egr valve is sticking.
junk it
Loose or defective gas cap.
A dead alternator is most likely. Maybe the ECM but not likely.
It comes on and stays on when the abs computer detects a malfunction and sets a code.
The abs light comes on and stays on when the computer detects a malfunction and sets a code.
check your brake fluid it is probably low