Battery kill switch - Radio drains power

[dirtyroger]

Please help,

I've been running my van now for 6 months with this radio that drains my battery and i yet to have a leisure battery to run it off so i have to discontect the battery each time i leave the van. This is starting to get annoying and is making the battery connection a little dodgy.

Can any body explain to me simply how i could make a kill switch that i could put on my dash using cheap Maplin components.

I've had a look around but can't find an answer and would love a diagram or a few pictures of peoples completed switches.

Thanks in advance

[syncrosimon]

This is what I have done with a 15 quid isolator switch, all joints soldered. Works well, I dont use the little fuse function now, as the fuse board is powered from the leisure batteries. She starts much better now with fresh earthing.







Simon.

[wee bugger]

Have similar issue with my radio and its permanent live(I think)...i just pull the fuse for radio/courtesy lights etc (third from left on mine...fuse box cover is broken off so easy access) Keep meaning to do something "better"

[weldore]

is there no way at all to get acc. position on the key ?
wont a golf barrel fit or summat?

[dirtyroger]

This is what I have done with a 15 quid isolator switch, all joints soldered. Works well, I dont use the little fuse function now, as the fuse board is powered from the leisure batteries. She starts much better now with fresh earthing.

Thanks! That looks like just what i need, what amp battery cable should i use (There seems to be loads!)?

If i use the fuse function you have shown should I take the one out of my fuse box?

I would like to possibly link this to my dash board any points you would make about this?

Thanks for answering these simple questions!

Like the green paint job!

[syncrosimon]

I was lucky to have all that spare wire included in the ambulance when it left the Finnish army, it has just been recycled in different places. The fat wire I think is a 60mm, the shorter one is 25mm. Need to get from a specialist like vehicle wiring products where that switch came from.

http://www.vehicle-wiring-products.eu/V ... ycable.php" onclick="window.open(this.href);return false;

simon.

PS. your radio should not drain that much, and should be good to leave for a fair few weeks. Is the battery a duff one??

[Globbits]

dirtyroger, before you start worrying about a kill switch, it may be that you've just got a hungry stereo. What brand is it? How new? What sort of power output? Also (most importantly) how's it wired up?

Car stereos have two +12v power leads - a red one and a yellow one. Normally, the red one is the permanent +12v feed (for keeping the settings when you turn the engine off) and the yellow one is switched on the ignition (for actually powering the stereo when you're listening to it). The principle reason for this used to be so that you could turn the stereo on using the "accessory" position on the ignition switch and be lazy about turning the units off. The main rason this is used these days is that stereos are still massively power-hungry, when in standby - that is, they are off but both leads are powered.

"Ok, I'm bored now - get to the good bit!"
If you have wired your stereo up so it can be on without the engine running (like most of us) you'll probably find that the stereo's still drinking the battery power even when it's "off". You can easily test this by simply disconnecting the switched-ignition lead on the stereo, leaving the van 'til the battery would previously have been drained and see if it's still alive.

If this is the case, all you need do is buy a cheapy-cheap accessory switch of your own style-choice and fit it in between the +'ve feed to the switched lead and the lead itself. Mount it on the dash somewhere nice and you can turn the stereo off independently of the engine, yet still have a battery that lasts more than a day

Hope that helps
Richard

[Rozzo]

This is what I have done with a 15 quid isolator switch, all joints soldered. Works well, I dont use the little fuse function now, as the fuse board is powered from the leisure batteries. She starts much better now with fresh earthing.





Simon.

that wont solve his problem. it will stop anyone starting the van up cos the fuse will blow but anything low current like a stereo will get its earth through the fuse. you want this setup but with no fuse in between the poles

[dirtyroger]

If this is the case, all you need do is buy a cheapy-cheap accessory switch of your own style-choice and fit it in between the +'ve feed to the switched lead and the lead itself. Mount it on the dash somewhere nice and you can turn the stereo off independently of the engine, yet still have a battery that lasts more than a day

Richard

Thats absolutly perfect, nice and simple.

Thanks very much Richard

[getunder]

When I built a kit-car I bought an isolator switch with detachable key off Merlin Motors I think at Castle Combe Racing Circuit or from any kit car building supplier. See Mags. I mounted it in a hidden position inside the car so it helps security as well. Incidentally it is replica E-type jag convertible which is now languishing unused in my garage. Can't afford to run 3 cars.

[Globbits]

Thats absolutly perfect, nice and simple.

Thanks very much Richard

You're more than welcome. Just make sure you get the right wire - sometimes the red and yellow wires do the exact opposite of what I've described! You'll know you've got the right one when the stereo remembers the radio stations and CD-position