Installing kill switch

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Hitech

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Do these only "kill" the power to the coil? I am going to install one on my boat (it doesn't have one) and I was wondering if I have to run wiring back from the coil or can they kill the power from the key switch?

Thanks.
 

Mark42

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Re: Installing kill switch

Do you mean a lanyard safety switch? They are intended to be wired into the ignition circuit. So when the lanyard is yanked out as you fall overboard, the ignition has its power cut, just like you turned the key to "off".
 

Hitech

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Re: Installing kill switch

Do you mean a lanyard safety switch? They are intended to be wired into the ignition circuit. So when the lanyard is yanked out as you fall overboard, the ignition has its power cut, just like you turned the key to "off".

Yup, that's what I mean. I was hoping to not have to run wiring back to it from the coil, but it seems that's how they work. Thanks.
 

Mark42

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Re: Installing kill switch

You don't have to run wire back to the motor, it can be wired right into the ignition switch at the helm.

Generally speaking, most boat ignition switches have an always on 12v wire from the battery. When the key is turned to the "on"/"run" position, the 12v is connected to the ignition wire, sending power back to the ignition circuit, allowing the motor to run. The lanyard is wired into the ignition wire at or near the ignition switch in such a way as to make the ignition wire take a detour through the lanyard switch. So when the lanyard is disconnected, the ignition is shut off. If you put the lanyard in the dash near the ignition switch, it should be easy to make the connections. You just have to identify which wire is the ignition circuit.
 

Silvertip

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Re: Installing kill switch

There are three types of kill switches so make sure you understand which type you need. Type 1 - Two Stroke Outboards Only: A kill switch for a two stroke is OPEN when the engine is running. When the lanyard is pulled the switch closes to short the ignition to ground. Type 2 - Four stroke, coil ignition systems: This type of engine (I/Os for example) require just the opposite. These ignition systems must have the circuit closed during operation. Pulling the lanyard OPENS the circuit to kill the engine. Type 3 - Universal: This type of kill switch can be used in either application, but you need to understand what system you have.
 

Hitech

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Re: Installing kill switch

TType 2 - Four stroke, coil ignition systems: This type of engine (I/Os for example) require just the opposite. These ignition systems must have the circuit closed during operation. Pulling the lanyard OPENS the circuit to kill the engine.

This is what I have. I was wondering if the switch is capable of carrying enough current to handle cutting all of the "ignition" current from the key switch or if it has to be in the coil circuit only. Do you believe I can just put it in the circuit straight off the ingition switch (key switch)?

Thanks.
 

Hitech

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Re: Installing kill switch

So far, one vote for straight off the ignition switch. That certaily would make it a very easy installation.
 

fixb52s

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Re: Installing kill switch

OK, I installed one today. I have a 140 Mercruiser. I used one of the universal switches. I will try to explain here how to set it up with this Mercruiser system, but other I/Os should be similar.​

This laynard kill switch had 4 prongs on the back. 2 are labeled "M" and 2 are "C". What this means is magneto ignition (2 stroke) uses the M prongs(circuit open with switch in the "run position") and a coil ignition (4 stroke) uses the 2 C prongs (circuit closed in run).​

The ignition switch has 3 connections. One is 12v power coming from the battery (red). The second is a purple wire that powers the ignition side of the house, along with the gauges. The third is a yellow wire that goes to the starter circuit. What you use here is the ignition lead, or purple. You cut the purple ignition wire and attach it to the switch "C" prongs. Note: your wire colors might be different.​

Here is a diagram I just whipped up to show it. Sometimes, pictures explain it better.​

Piece of cake!​
 

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wca_tim

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Re: Installing kill switch

How does it seem to wprk for you and where did you get it? It's clearly time for one in my boat. Thanks for saving me the time of asking the same question you just did!
 

fixb52s

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Re: Installing kill switch

I got it because of some of the stories I read about people hitting wakes and being thrown from their boats. The bay can get choppy, so I would rather be safe than sorry.​

I put mine next to the ignition switch and it does not get in the way of anything. I have yet to take the boat out with it yet, but I know it works (checked it with the engine running on the hose).​

I have the Seadog Universal Kill Switch found here at IBoats
 

Silvertip

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Re: Installing kill switch

Yes -- the kill switch on a coil ignition system connects in SERIES with the ignition circuit from the key switch. You disconnect the ignition wire from the key switch. One wire from the kill switch goes to the terminal on the switch where the ignition wire used to reside. That wire connects to the other terminal on the kill switch. If the key is turned off the circuit is opened and if the lanyard is pulled the ignition circuit is opened. Either way the engine dies. It is opposite on a two stroke where the kill switch parallels the ignition circuit.
 

Hitech

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Re: Installing kill switch

Thanks everyone. I was hoping I could install it that way. Should be very simple.

Thanks again. :D
 

Joshto

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Hi All, sorry for reviving this old thread.

In this post, I found most of the answers to my questions about Kill Switch installation except one which the OP asked but never got a replied for.
"I was wondering if the switch is capable of carrying enough current to handle cutting all of the "ignition" current from the key switch or if it has to be in the coil circuit only".

I noticed the purple cable is as thick as the Red (battery) which seems to suggest it handles high current. The Seadog Kill switch is rated for 5 Amps max. Is that enough to withstand the ignition current plus whatever accessory feeds from the purple wire when the engine is running?

Thanks
Josh.
 
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