Sticker Battery Master Switch

Battery Master Cut Off Switch FIA

Maintenance requirements

Alternator warnings


Mounting Instructions for Hella Battery Switch


Battery Master Switch and Cut Off Switch

The battery master switch can be used between the negative battery terminal and ground lead to the car body. This is the most common application for this kind of switch, and only useful when the engine is not running!

This type of connection has no security aspect to stop a rotating engine.
The engine runs on by the output voltage of the alternator!

Basic diagram switching of the negative battery terminal and ground

Basic diagram master battery switch

Battery Master Cut Off Switch (FIA)

To stop a running engine, switching off the main electrical circuit between the positive pool and the starter/alternator must be done. To avoid damage to de alternator (diodes), a keramic resister should be used between alternator B+ and ground, including the cut off ignition between terminal 54/15 and the ignition coil terminal 15.

Therefore you need a modified mainswitch with built-in two secondary switches, see the diagram below.

Diagram battery Master Cut off switch for NSU

Battery master cut off switch

Maintenance requirements

It is recommended to check ones a year the positive lead and the ground connection of the battery and all other connecting leads to the car body.

Alternator fitted cars with a very flat battery cannot be pushed or tow started.
There is not enough current available to begin the current generation cycle.

The most important is the starter motor circuit. Ensure that the connections in the main supply lead remain tight, clean and free from corrosion.

Alternator warnings