The cutouts will use a 2-way button and you have to hold it (both ways) to make it work. You could try holding it a few seconds while the engine's running to see if anything happens.
It is probably for the alarm. It's like a valet mode button or something like that. Just trace the wires and see where they go.
It is probably for the alarm. It's like a valet mode button or something like that. Just trace the wires and see where they go.