Battery Isolator Cut-Out Switch Location anyone ?

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mgcjag
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Re: Battery Isolator Cut-Out Switch Location anyone ?

#21

Postby mgcjag » Thu Jan 12, 2017 1:02 pm

Hi Rory.....I dont think there is any real argument for doing it either way.......having it on the earth side might make it easier to discnect the terminals without a short, but then i would always disconnect the earth first anyway.... ...haveing it on live side makes it easier to have aux circuits ..clock, alarm etc....
Steve
1969 S2 2+2 & Building a C type replica

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Re: Battery Isolator Cut-Out Switch Location anyone ?

#22

Postby Hugo » Fri Jan 13, 2017 12:03 am

Somebody mentioned security; it would take a competent car thief thirty seconds to figure this out and overcome it. I always fit a hidden switch to the fuel pump. That way, anybody can start the car (and if it's a convertible you can't stop them getting in) but they will get half a mile up the road and it will inexplicably conk out. Then they will have to do some serious head scratching & poking about under the bonnet to try to figure our what has gone wrong. I have done this on my wife's Morris Minor tourer and every other car I have had with an electric pump.
Hugo Miller - rebuilding an imported Series II OTS & converting to RHD

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Re: Battery Isolator Cut-Out Switch Location anyone ?

#23

Postby Hugo » Fri Jan 13, 2017 12:05 am

Forgot to say I once fitted a heavy duty permanent relay to the battery earth on an Aston Martin I owned. This was located near the battery and operated by a hidden light-weight switch inside the car.
Hugo Miller - rebuilding an imported Series II OTS & converting to RHD

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Re: Battery Isolator Cut-Out Switch Location anyone ?

#24

Postby dal2.0litrefrogeye » Fri Jan 13, 2017 11:59 am

Hugo , "half a mile up the road " ???? Wow your E is good on fuel :lol:
Its a way of life not a hobby

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Re: Battery Isolator Cut-Out Switch Location anyone ?

#25

Postby Hugo » Sat Jan 14, 2017 3:47 pm

dal2.0litrefrogeye wrote:Hugo , "half a mile up the road " ???? Wow your E is good on fuel :lol:


That is what a Morris Minor will do one ONE carb full! :-)
Hugo Miller - rebuilding an imported Series II OTS & converting to RHD

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Re: Battery Isolator Cut-Out Switch Location anyone ?

#26

Postby rfs1957 » Tue Dec 05, 2017 7:22 pm

Here's a picture to confirm what worked for me.

Image

The cut-out is indeed in the earth-strap, fitted as suggested in a foot-well blanking plate and with a 2A fuse in the jumper-wire that's hidden by the washer-bottle, to feed the clock and the interior lights.

Image

It's done about 6 months / 6.000 km now and works perfectly, tho' I've blown it a couple of times inadvertently when forgetting to turn the Big Red key before the ignition one ......... learning curve.

Image

Just enough room between the key and the fire-extinguisher, phew.
Rory
3.8 OTS Cream 877393 Built May 28th 1962
1978 Mini Van
(plus bevel and belt single-cylinder Ducatis)

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Re: Battery Isolator Cut-Out Switch Location anyone ?

#27

Postby ralphr1780 » Wed Dec 06, 2017 12:34 pm

Hi Rory, interesting, just realized that you have a RHD...
I would be worried that the passenger would inadvertently knock the cut-out switch while cruising, could be troublesome.
Ralph
'69 OTS + '62 OTS - Belgium

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Re: Battery Isolator Cut-Out Switch Location anyone ?

#28

Postby Hugo » Wed Dec 06, 2017 4:05 pm

I would put it on the 'live' side (i.e. neg in your case) or you will blow the radio fuse if you try to start without turning it on (assuming you have a radio with a memory that needs a permanent feed). If you put it on the ground side you will have to re-set the radio memory every time. Make sure the radio has its own low-amperage fuse though ;)
Hugo Miller - rebuilding an imported Series II OTS & converting to RHD

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Re: Battery Isolator Cut-Out Switch Location anyone ?

#29

Postby rfs1957 » Wed Dec 06, 2017 4:41 pm

I think your fears are unfounded, Ralph, as unless you carry kids in the footwell, or had a contortionist, they would have no chance of getting at the switch, or kicking it by accident, and the position of the extinguisher actually acts as a good foil.

Have you seen one close up ? They require a rotational movement, and are not a "switch" in the conventional sense - and furthermore there is a spring-loaded indent you have to overcome to operate them.

BUT you'd be right that it's easy to inadvertently unclip the rearmost extinguisher fly-off with your stilettos !
Rory
3.8 OTS Cream 877393 Built May 28th 1962
1978 Mini Van
(plus bevel and belt single-cylinder Ducatis)

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Re: Battery Isolator Cut-Out Switch Location anyone ?

#30

Postby ralphr1780 » Wed Dec 06, 2017 10:18 pm

Hi Rory, I do have 2 of these switches in hands and the indent is only when you want to switch on, but not for cut out. And in fact you can connect a pull wire with a red handle to cut out (similar to a trunk release), just a simple pull would rotate the handle.
...unless you have a different switch model?
Ralph
'69 OTS + '62 OTS - Belgium

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Re: Battery Isolator Cut-Out Switch Location anyone ?

#31

Postby rfs1957 » Thu Dec 07, 2017 7:19 am

Sorry Ralph, I don't get it.

During the two weeks and 5.500 km we spent this summer with a footwell full of travelling stuff, bags, picnics, and with endless getting in and out of the car, I don't believe any of my passengers ever managed to even touch the switch.

Operating it requires an effort, and even if you were to try to catch the "ear" with a forward movement your foot when getting in, as positioned you are actually pushing it against its stop and not moving it to "off".

Believe this is a non-issue.
Rory
3.8 OTS Cream 877393 Built May 28th 1962
1978 Mini Van
(plus bevel and belt single-cylinder Ducatis)

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Re: Battery Isolator Cut-Out Switch Location anyone ?

#32

Postby JagWaugh » Thu Dec 07, 2017 9:10 am

Hugo wrote:I would put it on the 'live' side (i.e. neg in your case) or you will blow the radio fuse if you try to start without turning it on (assuming you have a radio with a memory that needs a permanent feed). If you put it on the ground side you will have to re-set the radio memory every time. Make sure the radio has its own low-amperage fuse though ;)


You can interrupt either side of the battery. It's generally safer to interrupt the earth when you have to bring a cable through a bulkhead - in this case if the earth cable should chafe then all that happens is that your cutout isn't really a cutout anymore. If you chafe through a power cable then your cutout switch will become a melted mess, same as the rest of the car.

Radio... memory? Bah, humbug! (and you can also put a small bypass fuse across the switch when it is on the earth side)

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Re: Battery Isolator Cut-Out Switch Location anyone ?

#33

Postby rfs1957 » Thu Dec 07, 2017 10:09 am

My Swiss friend is bang on the nail.

Using a cut-out to interrupt either the earth-side or the live-side (and polarity is quite irrelevant) presents the same problems and accepts the same solutions.

In both cases, wherever the cut-out is sited, items like a radio, or - more importantly - interior lights and the clock, require a fuse across the cut-out to keep them fed, and both cases present the problem of forgetting to switch the Big-Red-Key before turning anything more important on.

Or those items would have to be fed from before the cut-out which I think detracts from the protection a cut-out affords, and is of course only applicable if the cut-out is in the live side - as you can't selectively manage earths to interior lights, clock, and radio.

On balance, and having lived with this for a while now, I think the evidence comes down heavily in favour of earth-interruption on any vehicle, and particularly on the E-Type where the 1) wiring lends itself so perfectly to such an installation and 2) has the perfect blanking plate in the footwell for the switch-mounting.

Please remember, too, that a live-side cut-out then presents two more big and unprotected live points that you have to insulate against accidental spanner or component contact ...........

(Can't speak for LHD - is the reasoning very different ?)
Rory
3.8 OTS Cream 877393 Built May 28th 1962
1978 Mini Van
(plus bevel and belt single-cylinder Ducatis)

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Re: Battery Isolator Cut-Out Switch Location anyone ?

#34

Postby ralphr1780 » Thu Dec 07, 2017 10:47 am

Hi Rory, :salute:
I have 2 models:
One 6 poles, like this: http://rrs-direct.com/store/ensemble-co ... -5155.html
Second is a 2 poles, guessing like your's, like this:
http://rrs-direct.com/store/coupe-circu ... clefs.html

Both use the same key: press it in and rotate clockwise for on, rotate CCW and it will cut and pop off.
The switch can be fixed under the bonnet, and the release cable passed through the bulkhead under the dashboard to a convenient location within driver's reach. In case of urgent need (and even while still keeping your eyes on the road), or when parking, just pull it for cutout. But of course, you will need to open the bonnet to replug and set on...

I still haven't fixed any, as soon as done will post pics.
Meanwhile, finishing the hood adventure inspired by your's!
Ralph
'69 OTS + '62 OTS - Belgium

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Re: Battery Isolator Cut-Out Switch Location anyone ?

#35

Postby Hugo » Thu Dec 07, 2017 11:02 am

I rebuilt a DB6 a few years ago - battery in the boot. I put a bloody great relay next to the battery operated by a (fused) hidden switch under the dash, and EVERYTHING (starter included) went through that relay. Can't remember now which side of the battery it went from though, not that it makes much difference.
For some reason Astons don't put a fuse in the clock circuit, which has led to at least one car going up in flames that I know of.
Hugo Miller - rebuilding an imported Series II OTS & converting to RHD

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Re: Battery Isolator Cut-Out Switch Location anyone ?

#36

Postby JagWaugh » Thu Dec 07, 2017 11:50 am

I much prefer working on a car which has a cutout switch.

In my experience the handled type rarely fail, but the ones with a green knob which fit on the battery post fail quite often (This may just be cheap ones that were sold here - you can get them in any hobby market shop).

AES sells various ones: https://www.autoelectricsupplies.co.uk/search?search_string=isolator+switch&x=24&y=16

I've fitted a few from AES, the lucas SSB ones with a black head work well, and they aren't quite as "in your face" as the red ones.

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