Ignition System: Operation
The distributor contains an electronic pulse generator, consisting of a pick-up coil and a reluctor (polarity wheel). As distributor shaft turns, reluctor teeth approach and pass the magnetic pick-up coil. See Fig 1.
As the reluctor teeth break the magnetic field around the pick-up coil, it causes signals to be transmitted to the amplifier module. The signals open and close a transistorized switch in the module. This turns the primary circuit of the ignition coil on and off. When the primary circuit is switched off, a high voltage surge occurs in the secondary circuit, firing the spark plugs.
The amplifier module has 4 terminals. Terminals "W" and "G" are connected to the distributor magnetic pulse generator (pick-up coil). Terminal "B" is connected to the coil positive terminal. Terminal "C" is connected to the coil negative terminal. See Fig 2. The unit is grounded by its mounting bolts.