Wiring in a battery isolation switch

[Marsu]

Electrics is not my strength, but I want to wire in a battery isolation switch.

I have the dash and the main harness out and am about to install a replacement harness that is undamaged (unlike the one removed).

I assume I need to supply a feed to the switch from the battery and then loop back to the two brown wires that connect to the Lucas fused connector near the battery and wiper/washers.


I would be grateful for advice.

[Beans]

I'd put the switch in the battery's earth cable.

<center>
<font color="blue"><i>1980 TR7 DHC (my first car, now restored and back on the road)
1981 TR7 FHC Sprint (better known as 't Kreng)</font id="blue">
<b>[url="http://www.tr7beans.blogspot.com/"]<u><b><font size="2"><font color="red">My Weblog</font id="red"></font id="size2"></b></u>[/url]</b></i></center>

[TR Tony]

I would agree with Theo - effectively isolating the battery from earth is simpler & just as effective.

I got one of those adaptors that goes on the battery negative post, between the battery & the earth cable, with a screw type isolator that you can use to just isolate the battery or remove completely as an anti theft precaution.

Fitted in a few minutes & works perfectly.

Tony

<font size="1">1981 2L FHC Cavalry Blue
1980 3.5L V8 DHC Jaguar Regency Red - sadly sold!
1977 TR8 FHC EFI Factory development car Inca Yellow</font id="size1">

[Odd]

This all depends on what car you're working on, where it's got/you intend to put the battery, how neat
and discreet you want the installation - etc. If your car (like my TR8 and dads TR7V8) have the battery
in the rear of the car - I'd most definitely recommend fitting a remotely switched battery isolator (like
this one http://www.vehicle-wiring-products.eu/VWP-onlinestore/battconns/photo/60532.jpg) outboard
of/behind the battery; http://i278.photobucket.com/albums/kk107/OddHedberg/circuitbreaker.jpg
remotely controlled by a switch that is hard to operate without direct intention. (A key operated or a
rotary switch for instance, positioned in the centre panel.) Something like this. http://i278.photobucket.com/albums/kk107/OddHedberg/Circuitbrakerisolatorswitches.jpg)

Then you'll have the best, and most discreet, solution. And since you have the harness out I'd recommend
fitting the 0.5 mm2 wires to/from the control switch <u>into</u> the harness - and they will be out of sight as well...

Don't forget to change the fuse centre out for a modern, reliable blade fuse centre
- while you have it all apart and accessible!!!

<font color="red"><b>My two 1980 Wedges...</b></font id="red">

[Marsu]

Thanks all for suggestions.

Odd, that looks like a great approach, but is beyond the scope of work I intend at this stage.

If I ever get around to moving the battery to the boot that is definitely how I will approach it. Thanks fopr showing us all.

[saabfast]

Small point but bear in mind that if you have a modern radio you will need to run a separate permanent fused feed to the radio to maintain the settings if you switch the power or earth at the battery. Assuming you want the isolator for anti-theft purposes rather than competition there are battery disconnectors which have a fused bypass to keep radio/ECU settings. If someone tries to start it when isolated it blows the bypass fuse. (Of course, you might be like the Stig and want the radio whilst on the track!)

Alan
Saab 9000 Stg 1
Saab 9000 2.3 FPT Auto
'81 TR7 DHC