Ignition Coil
Coils are oil filled and are energized whenever the ignition switch is in the "ON" or "START" position. They contain a positive "BATT" terminal and a negative "TACH" (sometimes called "DEC") terminal and a single secondary terminal. A special connector attaches the green wire from the control module to the negative terminal ("TACH") and the wire from the ignition switch to the positive terminal ("BATT").
NOTE:
"DEC" refers to Distributor Electronic Control. This terminal is also referred to as the "Tach Test" terminal.