Checking the capacitor (Opel Kadett D)

The capacitor has a significant effect on achieving the required ignition voltage. It reduces the formation of sparks when the breaker contacts open, thereby preventing premature burning.

A capacitor malfunction can be judged by a badly burnt breaker contact, a weak spark, or difficulties starting the engine. Defective capacitors are extremely rare.

Visual inspection

Remove the distributor cap and lift the contacts with a screwdriver. If the burnt areas are blue, this indicates a faulty capacitor, gray and black burnt areas are considered normal.

With the distributor cap removed, turn the engine over with the help of an assistant. Observe the breaker contacts when starting. If there is a constant blue spark between the contacts, this indicates a capacitor malfunction. If the spark occasionally jumps, this is normal.