View Full Version : Wiring up my new battery and a kill switch - Advice please?!

Tom J
12-07-2008, 10:00 AM
I've read the old threads and I'm still confused.

I've got my Odyssey 680 battery, I've got my Dyno battery housing which I will mount on the passenger footwell bulkhead.

I need a kill switch and the associated wiring for it all.

Ponk used these people:


Looks like as good a place as any but I need to know what to specify from them!

I don't want to keep the terminals under the bonnet and whatever I fit should be FIA compliant. I'm running a standard S1 engine and wiring. Dash is chopped so access to the bulkhead for wiring runs is good.

Can anyone help me to work out what exactly I need to order please?

12-07-2008, 04:29 PM
Do you want it to be an FIA kill switch or just a battery isolator switch? I can tell you exactly what I did for the isolator switch but the FIA version involves a fair amount more wiring in. I used the leads ref: SSP/N with a few changes. They made them up specially for me with 10mm connectors on one end of eac lead to fit the terminals of the kill switch and in custom lengths. Great service!


Tom J
12-07-2008, 05:35 PM
I'm going for an FIA switch, just picked up the Autolec one today from Tweeks.

12-07-2008, 10:42 PM
The fia kill switch will come with a wiring diagram. Easy enough to do once you,ve sussed out the correct wires at ignition switch.

Tom J
13-07-2008, 07:55 AM
Looking at the diag. now I was wondering if I could tap into the wiring at the column or whether I needed to go into the engine bay to bypass things...

Right then! I'll make some notes as I go and if it works, I can make a sticky. If it doesn't, I'll just make a mess like usual ;)

13-07-2008, 09:54 AM
I fitted mine on my S2. Just using the wiring from the column.

13-07-2008, 10:24 AM
I thought the idea of the cutoff was to completely isolate the battery in case of an electrical fire, wouldnt that mean it would need to be fitted into the main battery cable?

13-07-2008, 10:38 AM
its a battery cut off, it grounds the power from the alternator via a ballast resistor. and it should cut off the ignition.

13-07-2008, 12:10 PM
I thought the idea of the cutoff was to completely isolate the battery in case of an electrical fire, wouldnt that mean it would need to be fitted into the main battery cable?

Yup, that and the ignition wiring so that it "kills" the engine rather than just cutting off the battery and potentially damaging the alternator.

13-07-2008, 12:27 PM
if you just cut off the battery... the car will still run for about 15 seconds.. untill the alternator stops producing enough current to run the ignition system..

hence why a propperly connected isolator grounds the current from the alternator.

13-07-2008, 01:35 PM
it'll run for longer than 15 seconds aswell

Dave P
13-07-2008, 06:38 PM
I bough one of these on Ebay today, i'll need one once we switch to the modified class. :rolleyes:

13-07-2008, 06:43 PM
it'll run for longer than 15 seconds aswell

thats about how long it took a 205 i had to alter (mates) which some how passed log book.. with it working incorrectly... which i was rather suprised at...

Tom J
13-07-2008, 08:55 PM
I understand the theory of what it does and why the alternator needs to be grounded through a load but I'm confused now!

The diagram shows battery +ve to the big threaded terminal on the switch, and the other to 'main feed to starter and all circuits, including alternator output' - I presumed that meant it goes in line with the wire that goes onto the +ve battery terminal? I need also to suss out what I should do with the earth having moved the battery - presumably I make a new one close to the battery, bare the metal back and get a good fix?

Then another take-off from that lead goes onto the terminal for the load resistor, to give the alternator's output an alternative place to go when you hit the switch. Does that need to go in-line with the alternator wiring? I thought it would...

Lastly the other pair of terminals connect the ignition switch to the coil, so that must be the wiring off the keyswitch on the column.

13-07-2008, 10:44 PM
Tom mine's earthed to a seat mount. very slight sanding needed just to get some metal showing for a good contact. As you say the switch is just mounted in line between the battery positive and the fuseboxes/starter motor. On mine (which is just an isolator switch not a kill switch) i've wired the fusebox leads to one side of the switch with the battery positive and the other to the starter motor. That way when I take the key out it isolates the engine but I keep my radio presets, interior lights and the small flashing light that makes people think I have an alarm working :p

13-07-2008, 11:06 PM
Tom J heres a photo of the back of my kill switch i jus happen to have. Its for my S2. The colour of the wires may or may not make it easier for you. Shame your so far away otherwise i could point you in the right direction. I cant even find the wiring diagram so cant help with that. From what i can remember the battery cable itself is self explanatory utilising the +ve side. A +ve feed is run from this to one of the smaller terminals. (You will need to look at the diagram). The ballast resisitor needs to go to ground. I used the radio ground as it was convenient. From memory the other wires are from taping into the ignition switch wiring. Cant remember which ones sorry. I know this is a bit vague but that all i can remember without the diagram and/or car in front of me.