All about U5

Connections

Low voltage connection

Most pencil coils have a low voltage connector with three pins: Ground, battery voltage, ignition signal.

Some only have two pins: Battery voltage, ignition signal

Versions with integrated ignition module may have a different layout.
 

High-voltage connection

Depending on the angle at which it is viewed, this connection is the end of the secondary coil or the connection point to the spark plug. Through this connection, the ignition voltage travels to the spark plug, where a spark-over occurs.

U5 category pencil coils are positioned directly on the spark plugs. An ignition cable is not required.