Bringing Down The Bus: Battling A BMW No-Crank
I arrived at the shop and verified the no-crank condition. The dash lit up brightly, but no starter action was forthcoming. Beginning with the basics, I tested power supply at the ignition switch, behind the Car Access System (CAS). This is the module in which the key is inserted. Power and ground was intact; I tested at the starter and found actuation voltage unavailable for starting.