Kill switch quandary

[supermanotorious]

Wondering if what I want to do can be done.... I have a voltmeter installed in the unused fascia of the air box which is a constant drain on the battery. I would prefer it only gets either the power or ground, when the kill switch is not engaged, simply when the engine is set to "On" or "Run". For this matter I would like to install a back-lit rocker switch for the kill switch, which lights up when the engine is "On" or "Run". But the kill switch simply grounds the ignition wire when engaged. Now, if I wanted it to light up when off, I would simply pull ground from the ignition wire but I want the opposite. How to do?

 

[supermanotorious]

I'm really trying to think this through, would a relay help?

 

[supermanotorious]

What?! Am I crazy? Is this physically impossible?

 

[HippieHeadShot]

Assuming I understand what you are wanting.

No

you'll need to run a switch between the power line and keep it independent. So 2 switches to keep it simple. So once you have it on, hit the new switch to deliver power

The problem is your wanting to complete a circuit, but one is a ground and the other is live. You don't want to run live wires to your ground kill switch.

The only option I could think of is a double layered toggle switch, it would have 6 pins: 2 ground lines 2 acc on and 2 line in(power). This would let you run both the hot and ground with a simple on off, problem is they are hard to find.
This way when the kill switch is not engaged you can have live power to your gage, and when the killswitch is on power would be cut to the gage.

Hope this helped, clarify what you want if its not.

 

[supermanotorious]

I think we're getting somewhere. Truth be told I didn't know about 6-pin toggle switches but that's exactly why I created this thread. THIS might be exactly what I'm looking for. Thank you Hippie!

 

[anderkart]

I agree with HippieHeadShot.
Those type of switches are called a DPDT (Double Pole, Double Throw) switch. They're available in toggle, rocker and push/pull type variety's, plus with the illuminated option or not.
Check out this search link: https://www.google.com/search?q=con...d=0CAYQ_AUoAA&dpr=1#q=illuminated+dpdt+switch

 

[supermanotorious]

well well well, look what I picked up. Fry's Electronics for about $4. I am going to check Radio Shack in a couple hours when they open to see if I can find a switch with back light. If not I'll probably just order the batch of 25 online

 

[supermanotorious]

Now, how do I wire the doggone thing? Google images aren't helping

 

[supermanotorious]

I know I could create some inline fuse holders and start testing different configurations but I'd rather just get it from the get-go, how about this configuration? But then again, this switch only has 2 positions so I dunno....

 

[HippieHeadShot]

Hey can you post a pic of the underside, and which pegs are which and I'll give you the set up. You just want to make sure you don't send power the wrong way!

Sorry about the slow reply, I've been working like mad.

 

[supermanotorious]

here you go! thanks!

 

[HippieHeadShot]

That's an AC switch, you'll want a DC switch. That's the danger of an electronic store, there 99% ac. You need to check you auto parts store because they will be made for a 12v DC system.

That said you *can* use it if you have to. But you could burn it out because of the arc when used under load.

That said I'll draft up a quick pic and add it for how you should wire it.

 

[supermanotorious]

Please draw it up as I'll be ordering online any way, I don't think even close to 10A will run through this switch, I just want it to send a signal to the volt meter for now.

 

[supermanotorious]

This one might work. It's a 14V 21A switch

http://www.delcity.net/store/Illumi...=38094426869&gclid=CLm07YWD9MQCFUc2gQodO6oAkw



EDIT: crap, that's just a 5-pin, would it still work?

 

[Joe-405]

Auto zone used to carry the dpdt switches when I worked there. But they have been downsizing there electrical stuff over the last few years.

Your best bet is probably napa local.

 

[HippieHeadShot]

Sorry I did not reply sooner!

This one might work. It's a 14V 21A switch

http://www.delcity.net/store/Illumi...=38094426869&gclid=CLm07YWD9MQCFUc2gQodO6oAkw

EDIT: crap, that's just a 5-pin, would it still work?

No it needs to be an unbridged DPDT 6 pin.

For this to work make sure the switch 6 pin you get is a dpdt.

Here is one that should work. (double pole, double throw) that's 2 circuits that have one on/off switch. Make sure the dpdt doesn't have a bridge that connects the 2 circuits.

https://www.fruugo.us/dpdt-centreof...ZppnZbAGmi7zvwZrDwEXSGaM2_tXnXGHtCBoCs3Pw_wcB

Okay so what you need to do is pull the original kill switch off. now take the line going into the kill switch and connect it to the "A" side of the circuit on the 6 pin's "power in"

Now attach the ground going out from the original kill switch to the "acc on" of the "A" side circuit. then cover the ground on the "A" side circuit so that it doesn't ground thus acting like the original killswitch.

Take the power line connected from the battery positive to the voltage meter, remove it and connect the battery line to the "power in" on the Second Circuit of the 6 pin, the "B" side.

Run a wire from the "acc on" of circuit "B" to the positive power line of your voltage meter. So when the switch is on power will flow from the battery to the voltage meter.

Connect to the switch's ground on the "B" circuit to solid ground, I recommend wherever you have the voltage meter grounded.

Assuming you've done this correctly when you turn the switch on the ground will connect (as though the kill switch is "off") AND power will be turned on to your voltage meter.

Hope this helps, if you need more info let me know!

Hippie

 

[HippieHeadShot]

Here is a quick diagram I did on my phone for you.

https://docs.google.com/file/d/0B8YiUSQSP_L4ZEtZaFBsQ2xCOTg/edit?usp=docslist_api

 

[supermanotorious]

I get Popular Mechanics and Popular Science since the wife won't let me get the other magazines I like and they've been advertising this book for some time. I finally bought and it and while I haven't read the entire thing, check out this page I found- crazy.

But this is telling I probably wont find this switch in the back lit rocker style. I suppose I could put a LED near the switch to indicate as well.