Dead mans Switch

[stikineriver]

I have a 25' Svendsen Marine Works aluminum jet boat with a 496 Marine Power EFI, and a Hamilton 241 jet pump. I would like to install a dead mans switch but can't seem to figure out where to install it (what wire) The key swithc has 3 posts. The bottom post has a 12 ga wire from the battery. #2 post goes hot when the key is on and feeds power to the fuel pump & gauges and #3 post goes to the starter. I tried pulling the fuse in the wire coming from post #2 while the motor was running. The gauges went to zero, but the motor did not stop. I coulud not tell if the fuel pump stopped, but after 1 minute with the motor still running, i figured if i went over, 1 minute running time was to long. Can anybody tell me how to hook up a switch? I have switch & lanyard for a Yamaha ob, so i assume it will work.

 

[JustJason]

Re: Dead mans Switch

it needs to cut power to the ignition circuit.
If the key has 3 posts... 1 will be battery power to the switch. Then 1 output will be for the ignition. The 2nd will be the start wire.
Figure out which one is which. Then disconnect the ignition wire and run that through an emergency stop switch, then back up to the keyswitch.

 

[Don S]

Re: Dead mans Switch

Put the kill switch in the PURPLE wire between the key switch and the engine.

 

[Silvertip]

Re: Dead mans Switch

An outboard kill switch will not work. Outboard engines "short" the ignition to ground to kill the engine (it's a magneto ignition remember). I/O or inboard engines must "make" the circuit in order to run and they "open" the circuit to stop the engine so the ignition works opposite from an outboard. If you usebd that switch you would not get the engine started until you pulled the lanyard. You need a switch that is closed when the lanyard is installed. O/B switches are "Open" when the lanyard is installed.

 

[stikineriver]

Re: Dead mans Switch

I found a switch at iboat.com. If i took the fuse out of the wire from post #2, why did the motor not stop?

 

[Don S]

Re: Dead mans Switch

Got a link to that particular switch? Forgot about the OB's being just opposite as Silvertip stated.

 

[stikineriver]

Re: Dead mans Switch

http://www.iboats.com/Cut_Off_Switc...04609283--**********.074416176--view_id.45138

 

[MikDee]

Re: Dead mans Switch

An outboard kill switch will not work. Outboard engines "short" the ignition to ground to kill the engine (it's a magneto ignition remember). I/O or inboard engines must "make" the circuit in order to run and they "open" the circuit to stop the engine so the ignition works opposite from an outboard. If you usebd that switch you would not get the engine started until you pulled the lanyard. You need a switch that is closed when the lanyard is installed. O/B switches are "Open" when the lanyard is installed.

Maybe I'm wrong but it seems that this switch should work, if you think about it, 3 wires, 2 of them complete the ignition circuit when the lanyard is in, then, pulling out the lanyard breaks the ign. circuit, and the 3rd wire also grounds out the coil. No?

 

[JustJason]

Re: Dead mans Switch

No no Mikdee....
3 wires...
1 comes up from the battery to power to ignition and starting circuits
1 goes out to power the starter solenoid (but only momentarily when the keyswitch is in the start position, i think this wire is usually yellow or a yellow/red.... but don't take my word on that one )
1 goes out to power the ignition circuit.

Switches come 1 of 2 ways... always. A switch is made as either a "normally open" or a "normally closed" type.
A keyswitch is normally open, and requires an action by the user to close, or complete the circuit.
An OB ESS is a normally open switch, and an action by the user would close or complete the circuit... doesn't matter if it's completing a power or ground loop.
An IB ESS is a normally closed switch, the circuit is always completed, unless an action by the user breaks or opens the circuit.

Stickeneriver... i believe don is right on the purple wire... however i'd double check it, because the color code is only correct if the guy before you knew what he was doing.
Most ignition switches are also labled on the back, you may be able to just drop the keyswitch and look at the back of it.
Hope this helps!

 

[Don S]

Re: Dead mans Switch

Either of those switces will work, they are universal, and can be used on either outboard or IO's. The instructions that come with them explanes how to hook them up.
It's not rocket science.

 

[Silvertip]

Re: Dead mans Switch

I looked at the link as well and it appears the kill switch shown has multiple terminals meaning it has both normally open and normally closed contacts. You would use the common terminal and whatever terminal is closed when the lanyard is installed. I was assuming the O/B switch was for outboards only. Shows again what happens when you "*****-u-me"

 

[MikDee]

Re: Dead mans Switch

No no Mikdee....
3 wires...
1 comes up from the battery to power to ignition and starting circuits
1 goes out to power the starter solenoid (but only momentarily when the keyswitch is in the start position, i think this wire is usually yellow or a yellow/red.... but don't take my word on that one )
1 goes out to power the ignition circuit.

Switches come 1 of 2 ways... always. A switch is made as either a "normally open" or a "normally closed" type.
A keyswitch is normally open, and requires an action by the user to close, or complete the circuit.
An OB ESS is a normally open switch, and an action by the user would close or complete the circuit... doesn't matter if it's completing a power or ground loop.
An IB ESS is a normally closed switch, the circuit is always completed, unless an action by the user breaks or opens the circuit.

Stickeneriver... i believe don is right on the purple wire... however i'd double check it, because the color code is only correct if the guy before you knew what he was doing.
Most ignition switches are also labled on the back, you may be able to just drop the keyswitch and look at the back of it.
Hope this helps!

Well jason I don't know what type switches you're talking about? It sounds like an average ignition key switch, but I was referring to that particular kill switch which apparently can be used both ways, as I thought might be the case.