How to wire a kill switch on a '77 Chrysler 135hp?

Captndrydock

Seaman
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Mar 9, 2020
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I have a lanyard kill switch with a black and red wire. Can I wire this to my key switch? If so, which terminals would they go to? Thanks in advance, much appreciated!
 

brodmann

Chief Petty Officer
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Jun 17, 2008
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426
On the back of your ignition switch, I believe it's a blue wire. When the key is in the "ON" position this wire sends voltage to the ignition system. Since your lanyard switch only has 2 wires, once you determine that the blue wire on the ignition switch has 12V when the key is "ON", but no voltage when the key is off, you've found the right wire. Remove that wire from the ignition switch. You'll want to install your lanyard switch between that terminal on the ignitions switch and the blue wire that powers your ignition system. The lanyard switch is only a switch, so the wire colors don't matter. Run a wire from that terminal on the ignition switch to one of the leads on your lanyard switch and the other wire on your lanyard switch will go the the blue wire.
 

Nordin

Commander
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Jun 12, 2010
Messages
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Yes as brodmann says if your engine has the Motorola Magna Power I ignition system.
It is a battery powered distributor ignition system.
First you have to check if your engine has a distributor, if not it can have the Prestolite system, the Magna power II system or has been converted to auto style battery system without a CD box.
Pics of the engine power head will confirm which system it has.
General is if the engine has the Magna power I system or a auto style your lanyard must open the circuit when you pull it (the switch in the lanyard should be closed when the lanyard is in place).
It should be wired as brodmann says.
BUT if you have the Magna Power ll or the Prestolite system the lanyard should have an closed circuit when it is pulled.
Prestolite system needs to be ground out to stop the engine and at the Magna Power ll the MB and MW terminals at the CD module need to be bridged.
 

Captndrydock

Seaman
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Mar 9, 2020
Messages
57
Thanks guys! This motor has the motorola magna 1 distributer system. So sounds like it's the normally closed switch that's used.

One thing that's still unclear Brodmann, one wire from the kill switch goes to the blue wire on the ignition switch( after confirming 12v). Where does the other wire go?
 

Nordin

Commander
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Jun 12, 2010
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The keyswitch has connection between the B terminal and the I terminal in ON and START position.
Connect the lanyard in series with the blue wire from the keyswitch.
The engine will kill if you turn the key to OFF or if you pull the lanyard.
The 12V power from the battery will be broken (off) when pulling the lanyard or turn the key to OFF position.
 

Captndrydock

Seaman
Joined
Mar 9, 2020
Messages
57
On the back of your ignition switch, I believe it's a blue wire. When the key is in the "ON" position this wire sends voltage to the ignition system. Since your lanyard switch only has 2 wires, once you determine that the blue wire on the ignition switch has 12V when the key is "ON", but no voltage when the key is off, you've found the right wire. Remove that wire from the ignition switch. You'll want to install your lanyard switch between that terminal on the ignitions switch and the blue wire that powers your ignition system. The lanyard switch is only a switch, so the wire colors don't matter. Run a wire from that terminal on the ignition switch to one of the leads on your lanyard switch and the other wire on your lanyard switch will go the the blue wire.
Thanks Brodmann, it took me a while to understand this, I don't why. But a friend just clarified it for me and now I get it! Thanks!
 

Captndrydock

Seaman
Joined
Mar 9, 2020
Messages
57
The keyswitch has connection between the B terminal and the I terminal in ON and START position.
Connect the lanyard in series with the blue wire from the keyswitch.
The engine will kill if you turn the key to OFF or if you pull the lanyard.
The 12V power from the battery will be broken (off) when pulling the lanyard or turn the key to OFF position.
I think I misunderstood you here. And not knowing what you meant by "in series".

To clarify, as I now understand it. Hook one wire from the lanyard to where the blue wire was on the key switch. Hook the blue wire to the other wire on the lanyard.

Is this correct?
 

Nordin

Commander
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Jun 12, 2010
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Yes, correct and if the lanyard has both a normally closed and a normally open function you should use the function that open up the contact when you pull the lanyard.
When i said in series I mean in between.
Blue wire at keyswitch to one of the wire at the lanyard and the other wire at lanyard to the terminal where the blue wire was at keyswitch.
 

Captndrydock

Seaman
Joined
Mar 9, 2020
Messages
57
Yes, correct and if the lanyard has both a normally closed and a normally open function you should use the function that open up the contact when you pull the lanyard.
When i said in series I mean in between.
Blue wire at keyswitch to one of the wire at the lanyard and the other wire at lanyard to the terminal where the blue wire was at keyswitch.
Perfect, thanks for confirming. I'm not too good with electrical, but learning a lot lately.
 
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