Ignition System: Operation
The distributor contains an electronic pulse generator, consisting of a pick-up coil and a reluctor (polarity wheel). As the distributor shaft turns, the 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, and terminal "C" to the coil negative terminal. See Fig 2. The unit is grounded by one of its mounting bolts through the alloy base.