Battery Master Switch

[Mat Norris]

Running a x/flow with a lucas rally ignition kit.

 

How do I wire in a FIA battery kill switch??

 

I guess I don't run the starter circuit through it??

 

There are two large connections and four small ones...

 

There is also a large resistor that it says to fir between the main electrical circuit and earth - not sure what this is for.

 

The ignition cut of is fairly simple - I guess I just cut into the feed for the ignition amplifier...

 

Hope you can help

 

Regards

[budgie]

Look in FAQ

[Peter Carmichael]

The main connections are for all current coming from the battery, so yes the starter motor circuit is isolated too.

 

The principle is that when you open the switch to kill the electrics, you are removing the battery from all circuits. This action also needs to forcibly drag the car operating circuits down to 0v, because the alternator is still happily spinning away, generating current.

 

The secondary connections and the resistor do this. What you need to do is check the continuity of the secondary connections in relation to the main connections. You are looking for an opposite behaviour on one pair of terminals. When the switch is "on", the secondary connections should be off (or open). When the switch is "off", the secondary connections should close.

 

You then wire:

- the battery positive to one of the main connections.

- the other main connection to feed all car circuits including the starter. Sometimes it is easiest to run one thick cable from the main terminal to the starter solenoid and have all other positive feeds also connecting to the starter solenoid. The alternator output should also connect to this. Basically all the wires that were previously on the positive connection of the battery get moved to the starter solenoid.

- you wire the resistor from the car side of the primary connections to one of the secondary terminals.

- you wire the other secondary terminal to earth.