Haorui supercharger throttle connection does not show gear down.

Ignition system failure, excessive carbon deposition in spark plug.

1. According to the query of Easy Car Network, the ignition system is faulty: the spark plug electrode gap is too large or too small, resulting in the display screen not showing the gear position.

2. Too much carbon deposit on the spark plug: the insulator of the spark plug is damaged, which will lead to too high voltage and the display screen will not show the gear position.