How do you arm the red bulb under your rear view mirror light on a 2002 BMW 325i sedan?
this will only light up if you have an alarm system. most BMW
are prewired for the alarm but may not have it activated. if you
the alarm then you can turn it on/off by holding the m button on
the radio for 10 sec. this will than prompt you thru the set up
function for the alarm.