<E30>What is the A - M rocker switch on my 325iC

[Mark Colasante <mcola@xxxxxxxxxxxxxxxxxxx>]

I have recently purchased a  1990 325iC, auto trans..  It has a rocker
type switch on the dashboard to the left of the rear defroster button.
The switch is labeled A on one side and M on the other.  It also has a
red light that never lights up regardless of the switch's position.  I
am assuming a previous owner added this switch.  Does anyone know what
it might be used for?

Thanks,

Mark Colasante
Columbus, OH
90 325iC

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