kill switch installation

[dave37]

Installed an "overboard" switch, 1985 Merc 500, 4 cyl. 2 stroke, 50 hp, s/n 7007633. Seloc wiring diagram showed A-F terminals as run position so I carefully installed it inline (series circuit)on the F terminal (white wire) wiring. Engine still runs with kill switch pulled. Am thinking of putting it on the A terminal wiring (red)which shows as positive feed to the ignition switch. Don't like the idea of taking control apart and fiddling with a test light on the live contacts of the ignition switch.<br /><br />Am I heading in the right direction here??<br /><br />Oh yeah, it's not a Merc kill switch, it's a Johnson switch (don't ask), so I don't have Merc specific instructions with the switch.<br /><br />Thanks!

 

[chuckz]

Re: kill switch installation

Bet your accesories turn off when you activate the kill switch.<br /><br />Your engine only use the 12VDC for starting. When the ignition is turned to the off position it either shorts two wires together, grounds one wire or opens a circuit. Look at your wiring diagram and see if you can figure out how the ignition switch kills the engine. Then wire the kill switch in parallel with the engine kill on the ignition switch.<br /><br />The only question is do you need a normally open or normally closed kill switch.

 

[Winger Ed.]

Re: kill switch installation

I think you have the wrong switch. You need one that closes or makes connection when you pull it.<br /><br /><br />That engine is like a big lawnmower with a electric start. When you shut off the engine, it has to ground the magneto. The key switch does two functions, it makes the connection and lets the starter hit, plus when you switch it off, it grounds the ign. circuit.<br /><br />I think its a orange wire on those that kills the engine when its connected to ground. Whatever wire color is used for the mercury (over) tilt switch on top of the engine normally goes on up to the key switch also. <br /><br />On the back of your key switch, it will be a wire that conducts to ground with the key in the 'off' position, but will not conduct to ground in the 'on' position.

 

[dave37]

Re: kill switch installation

Thanks. You're absolutely correct, this switch is closed with the lanyard connected to it, so I'm going to use a relay, energized by the 12V+ run wire from the ignition switch, in series with the kill switch so that when the lanyard is pulled, the kill switch opens power to the relay, and the relay provides a ground on the orange wire to kill the engine.<br /><br />Thanks!!!