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FIA switch and bike engine
iiyama - 15/2/09 at 08:02 PM

Seen this covered for cecs but I cant find anything for becs.

Can someone post a circuit diagram for a bec application?

Ta!

nitram38 - 15/2/09 at 08:54 PM

I'm using an fia switch that has secondary contacts. Instead of a resistor, because the bike engine is different to a car, I have used the second set of contacts to cut the ignition key pair. The main battery lead is cut and the ignition is cut to stop the engine from powering itself via the dynamo.
Hope that makes sense.

iiyama - 15/2/09 at 08:57 PM

You mean the kill switch is wired through a set of the secondary contacts? The ballast resistor isnt required then?

nitram38 - 15/2/09 at 09:04 PM

If you use just an ordinary fia switch, the battery can be disconnected but the engine will still run on as the electricity is still supplied by the dynamo/alternator.
The secondary contacts cut the ignition feed to the coils and so the engine stops.
The ballast resistor is on cars to protect the alternator diodes.
On a bec you are cutting the ignition and the battery together (unlike a car which normally has a seperate ignition key switch). You do not need the ballast resistor.

iiyama - 16/2/09 at 05:37 PM

OK bud, thanks for that!

Just to clarify completly:-

+ve from starter solenoid through FIA switch to starter motor.
-ve from battery through FIA switch to chassis
Take a cable off of bike kill switch through FIA switch and make back to kill switch.

Make sense? Right or wrong?

nitram38 - 16/2/09 at 07:34 PM

No!!!!!!!!!!!!!!!!!!!!!!!
On the main terminals you just break the positive lead of your battery.
On the secondary terminals you put the pair of wires that would normally be connected at your ign switch.

iiyama - 16/2/09 at 08:34 PM

Dont have an ignition switch so I use a wire from the start button? Why arnt +ve and -ve piped through the FIA switch then?

nitram38 - 16/2/09 at 08:50 PM

There is only one set of main terminals so positive and negative connected to these will give you a very big bang!
You will create a direct short between the battery.
The start cables are no good as they are only briefly connected to turn the starter motor.
You need to kill the ignition or the stop circuit to stop the engine.
You sound very unsure to me so I recommend getting someone to do this for you.

bigfoot4616 - 16/2/09 at 11:00 PM

why is the resistor not needed on a BEC?

nitram38 - 17/2/09 at 05:27 AM

quote:
Originally posted by bigfoot4616
why is the resistor not needed on a BEC?


Because unlike a car where you just switch off the ignition coil, if you use the ignition switch or stop on the secondary terminals, you are switching off relays that kill everything. This is no different to turning off the ignition switch on a bike.
The resistor is for when you are cutting the battery feed and ignition coil circuit on their own which can damage the alternator diodes. The resistor briefly disipates the residual current generated by the alternator.

[Edited on 17/2/2009 by nitram38]

bigfoot4616 - 17/2/09 at 08:03 PM

is that when you are using it instead of an ignition switch?

i'm using an ignition key and the fia switch is for emergency use and so i can also turn of all the electrics. normally i will use the ignition key to stop the engine.
i'm taking the coils/cdi unit feed wire from the ignition switch through the fia switch so will that still kill everything engine side of the electrics or will i need to use the resistor?

cheers

nitram38 - 17/2/09 at 09:32 PM

If you are using a seperate ignition switch then I would use the resistor. Just follow the wiring diagram

bigfoot4616 - 17/2/09 at 10:12 PM

cheers. i'll carry on as i originally planned, just confused myself reading this thread