Siba and Bosch Black Box Systems

Never remove the regulator cover with the battery connected. Accidental closing of the cut-out contacts often causes them to weld together. The engine starter will appear to be operating but using the charging part of the circuit that is not built for heavy starting current. This often destroys the cut out and at worst will cause a fire and/or other component damage. It is extremely difficult to adjust the charging cut-out and this requires specialist tools.

The electrical wiring for this system is shown below

The BOSCH black box system is broadly similar and the regulator has a black cover marked with the BOSCH name. Many have been replaced by the SIBA unit and both types are compatible operating with either BOSCH or SIBA dynastart engines. The picture shows a BOSCH ‘black box’ control system fitted to all KR200 models from chassis number 70643 reported date of introduction 6th April 1959.