Electrical Kill switch

Julian West · 02-16-05, 08:24 AM

Has anyone got any opinions on the positioning of the master electrical kill switch?

The RAC blue book states either at the base of the windscreen on the drivers side, or below the rear window.

Anyone got any ideas/suggestions experiences..??

Trevor Booth · 02-16-05, 08:56 AM

My suggestion is to have two switches. 1) a double pole switch located near the battery and operable from outside the vehicle. 2) located inside the vehicle in a position that the driver can reach (with belt on) It is common in OZ to also have the internal switch operable from outside by attaching a 0.062" wire cable to the lever, terminating with a large plastic ring (suitable for gloved finger) near the base of the RHS A pillar. The internal switch isolates the main power supply to the electrical circuit of the vehicle, The external double pole switch isolates the battery cables and the main power supply. This obviates the need to run heavy battery cables to the internal switch or an external switch at the A pillar.

Paul Thompson 'Hooligan' · 02-16-05, 12:44 PM

I would recommend fitting an all electric cut-out, such as the ARMTECH ISOLATOR .

This works well - can be mounted under the fron clip next to the battery (to break earth connection) and only requires a discrete 'button' on the exterior (lower part of driver door post) which can be marked with a suitable sticker when competing. [img]/ubbthreads/images/graemlins/smile.gif[/img]

One thing though - don't leave it energised continously when not using the vehicle as it draws more than the 0.1A they specify and will flatten a bettery over two or three days!
[img]/ubbthreads/images/graemlins/frown.gif[/img]

Trevor Booth · 02-17-05, 07:49 AM

My understanding - If you isolate the earth and not the power the engine may still run when you activate the switch as the alternator or generator can get a feed back earth and still supply power to engine electrics. suggest you check with auto elec. I have always used double pole switch which isolates + ve and - ve.

Paul Thompson 'Hooligan' · 02-17-05, 05:57 PM

Hi Trevor -

You're right, but the Armtech unit also breaks the output from the alternator back to battery +ve. (double pole?) - so there is no path for any generated output and hence motor will stop.

Trevor Booth · 02-18-05, 12:48 AM

Smart little device. I have asked for some info from them.

Regards

Trevor Booth · 02-18-05, 01:12 AM

Paul,
I dont suppose you have any other contact details for Armatech, My request for info was returned 'cannot find the url'

Trevor

Paul Thompson 'Hooligan' · 02-18-05, 08:36 AM

Hi Trevor

The link on my above post seems to be working - but you can also Try clicking here for a uk supplier namely Rally Design who now seem about the cheapest for such parts.

Hope this helps - [img]/ubbthreads/images/graemlins/smile.gif[/img]

John W · 02-18-05, 09:04 AM

That seems like an aweful lot of money for something so simple.

I have no doubt you could make something similar to this for a lot less than 30 quid (3 switches, some contacts, a relay, a lamp, and a little bit of logic).

I guess the only problem would be getting marshals to accept it is safe. Having said that ,how do Armatech get around this, as any accient that severed the wiring between the switch and box would render it useless...

Just a thought.

Cheers,
John.

Julian West · 02-18-05, 11:09 AM

Paul,

Thanks for the link, I wasn't aware of these devices. TBH I don't have a problem with the wiring, I'm happy to split the loom & wire the alternator direct to the kill switch.

My problem is finding enough space for the switch!! The B-post looks ideal (especially for wiring to the alternator) but the fiberglass is double skinned & the switch would interfere with the bulkhead paneling.

I've considered mounting the switch on the front clip, by the drivers side filler cap. But mounting would be a bit fiddly, as the key would have to be removed each time the front clip is opened.

Now I've looked, DT seem to sell a few different 'solid state' cutouts, but the Armtech unit looks best value. As you say, the push button is much easier to mount than a 'traditional' kill switch..

hmmmmm decisions decisions...... [img]/ubbthreads/images/graemlins/confused.gif[/img]

Julian West · 02-18-05, 11:24 AM

BLIMEY ! [img]/ubbthreads/images/graemlins/shocked.gif[/img]

At Demon thieves the price is 217.99 ukp +VAT

http://www.demon-tweeks.co.uk/catalogue/...ORT&from=search

At Rally Design the same item is 162.00 ukp +VAT

http://www.rallydesign.co.uk/catalog...oducts_id=2695

It really does pay to shop around!

Trevor Booth · 02-20-05, 07:37 AM

Thanks Paul,
I could view the armatech site but the request for info link failed. Rally Design site and info no probs
Regards,
Trevor

Paul Thompson 'Hooligan' · 02-21-05, 05:32 AM

Hi John -
I agree - it does seem a lot but no doubt, they have undergone extensive failure testing to ensure that a short circuit cannot initiate a fire etc etc.

Also - the circuit to switch off (isolate) is 'break active' such that if an impact damaged the wiring to either the internal or external 'kill button' - the unit would automatically isolate the power. This could also be linked in-line with a 'G-Switch' so that any impact of more than a cetain ammount would kill all power automatically. Malc has a G-switch fitted to his 40 so he can probably explain the ratings etc.

Thinking about it, if the wiring to the 'internal' dash mounted switch were damaged in an impact - I suspect that would be the least of your worries!! [img]/ubbthreads/images/graemlins/frown.gif[/img] ouch!

John W · 02-21-05, 04:56 PM

Paul,

thanks for the description on how it works.
To do what you describe can be done simply with a relay, nothing more.
Break active is not a problem either - just means the circuit is slightly different.
G switches are readily available too. Vauxhall have been fitting them since the early 80s. They used to be located in the base of the centre console on the astra and cavalier if you go looking for one at a scrappies. They have a manual reset button on them - often used by owners to immobilise their cars [img]/ubbthreads/images/graemlins/smile.gif[/img]

Cheers,
John.

Malcolm · 02-21-05, 05:07 PM

I have my kill switch at the base of the windscreen mounted on the front clip. Same with my fire extinguisher cable pull. I run all cables along the chassis to the hinge point of the front clip and then up inside the inner wheel arch to the point on the front clip at the base of the windscreen. Never had a short or any other real reliability issue. ALthough fire pull cable needs changing every so often. If you don't like that idea, make a bigger hole in the front clip so the key doesn't need removing each time. And cut the key down smaller. There is no regulation size for it that I am aware of. Just a common size.

My G sensor switch is a Jaguar item that kills the fuel pumps over 10g but could easily be made to work for more electrical isolation if required by use of a relay? Only triggered it the once which is not bad for the amount of off's I have had.

Malcolm · 02-21-05, 05:13 PM

Just a thought, when asked I have never advised anyone to put their kill switches etc in the B pillar position. To me this is not an officially sanctioned place. If you are hard up against a tyre wall there is no accessability for marshals to get to this position on the car. Hence on the upper surfaces.

However, so far no one I am aware of has been pulled up on this point.

Julian West · 02-22-05, 06:38 AM

It seems the 'best' or 'easiest' option is (yet again!) the most expensive one! [img]/ubbthreads/images/graemlins/crazy.gif[/img]

I'm leaning toward the Armtech unit, as it would be easy to fit a 'kill button' on the B post *and* on the front clip. It also makes an 'electric' fire extinguisher very tempting....