My brother bought a 1975 300D last week. After we took it for a drive, he couldn't figure out how to turn off all the lights. Rather than read the manual, he disconnected the battery. Now the engine won't even turn over. A friend who owns a BMW says that his car has a reset switch which disables the ignition circuit in the event of a loss of electric power. Does the 300D have such a feature? Or should we look for a bigger problem?