Battery cut off switch

[tomwood]

Have just bought a new battery but in order to avoid wrecking this one as well I intend to fit an isolator switch.

For those who've fitted their own could I ask:

1) Which one you went for an where is best place to purchase?

2) What additional bits are needed (extra wiring etc)?

3) Are there any good guides to follow on how to fit it?

If relevant, this is to fit a 2013 Duratec vehicle.

Many thanks,

Tom

 

[John Vine]

Do you want a pukka FIA master switch or simply an isolator?

JV

[tomwood]

Hi John,

Interested in both options. 

Tom

[Wrightpayne]

An FIA switch requires extra wiring to interrupt the live feed from alternator to the cars electrics so when you throw the switch it will stop the engine. You’d need to research how to do this on your specific car i.e. where to intercept the alternator wire and fit the load resistor to prevent frying the alternator when you throw the switch.

A simple isolator will not kill the engine but will stop such things as parasitic loads when off. You could fit an FIA switch as an isolator and wire up the alternator bit at a later stage.

hope that makes sense.

Ian

[Wrightpayne]

PS its usually an appendix in the build manual. Jonathan Kay is your man if you dont have a manual - he has most variants stored electronically.

Ian

[Tazio]

There is a Guide in the Guides section. I bought mine from SVC in Malvern now, they used to be in Tamworth.

[bluenose]

https://www.lotus7.club/guides/how-guides/fitting-battery-master-switch

[BigCol]

I did the same as Tom is contemplating.  I used an FIA switch as an isolator so didn't wire in the alternator/ignition switch bit (but did include the resistor - thought it was a capacitor - to prevent any spikes when switching the switch)

I mounted on it on the bulkhead so the switch is inside the car below the dashboard above the passenger footwell.  It meant the cabling to/from the battery was easy too:

I used this wiring diagram but without the lowest bit:

[tomwood]

Guys this is great info thank you.

BigCol - I like that idea, it’s a neat solution. I suppose it has its pros and cons though. On the plus side it’s an easier wiring job. On the negative side I guess it’s not really possible to reach the switch whilst sat in the drivers seat with a harness on?

having said that, Caterham fit them to the outside of the car don’t they, what’s the reasoning behind that? So a Marshall can throw the switch if the worst was to happen?

getting the proper FIA switch would seem to make sense even if I just used it as an isolator for now.

apart from Caterham themselves are there other places to purchase them from (noted the mention of SVC above, will look them up)

thanks also for the wiring diagram pic and link to the guide, much appreciated.

Tom

[John Vine]

Don't forget that you can reach the external FIA switch via the flap on the sidescreen, even with a harness on (at least, I can). So it's not just for the marshals.

JV

[BigCol]

I can (just) reach the switch from the driver's seat with harnesses on (because sometimes I forget to throw the switch having got settled-in...  though not as often as I realise my keys are still in my pocket having belted-up)

I found a cheap (cf Caterhsm) switch on the web via a simple google search.  I also bought spare keys.

[barry watts]

I  recently purchased one from Redline,  identical to the one I was replacing, and you get the usual excellent service. 

Baz.

[Domus]

 

though not as often as I realise my keys are still in my pocket having belted-up)

LADS top tip, keys on a lanyard around your neck.  

[tomwood]

John - I'm a short arse so the chances of me reaching it are low when harnessed up  

Searching some more, it looks like Caterham do a rather nice kit with all the bits in it including the various bits of new wiring although I suspect like most other things I'll be paying over the odds for it.

Thanks for the suggestion on Redline, will give them a call and see if they do a similar kit.

Tom

[Mark_]

Do have a link for that kit please ? Ive looked and not seen it on Cat  parts....

Cheers

[tomwood]

https://caterhamparts.co.uk/battery-leads/6675-battery-master-switch-kit.html

and there’s this one as well:

https://caterhamparts.co.uk/battery-leads/236-battery-master-switch-kit-ford.html?search_query=Master+switch&results=139

Tom

[Ian B]

Non-FIA switch here: https://www.carbuildersolutions.com/uk/battery-isolator-cut-off-switch-standard-version

Mount it through the bulkhead above the passengers knees, and use it to break either the positive or negative connection tot he battery to isolate it and prevent drain.

As long as you switch off engine with ignition switch first (eg don't use the isolator switch to kill a running engine) then it will be fine.

[BigCol]

I got mine via Amazon:

[Mark_]

Thanks for the links.

I know the Cat part seems dear, but its hassle free for me and comes with the right sized cable and all crimped up.....

[Tazio]

CC Prices are simply criminal

[Gridgway]

Thought I would add a question here rather than start a new thread.

The master switch that I have is well dodge, so needs replacing.  It's between the battery -ve and vehicle earth so will disconnect the earth and stop everything.  It's just the main switch without the other connections.

If the engine is running at this point, without the 3 ohm resister what is it that gets fried?  I think it's the alternator.

To be able to stop that (when using a cleverer master switch with the engine running), is there a way of doing it on the earth side, or do I need to wire it in the positive side as per the diagram above?

I will probably be happy just having it as an isolator rather than a kill switch , just wondering what the options are.