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eliminate the key switch

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has anyone bypassed the key switch? will leaving the key on kill the battery?

it looks like a 2pole switch that closes one set of wires and opens the other set.

I can see that one set being HOT with the switch ON should be for the ignition but what is the other set for?

What needs to be connected in the off position, that needs to be disconnected in the on position?

I would like to run just a kill switch on the bars and get rid of the switch.



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I like having a key most of the time.  I usually leave in turned on all day when riding, never had any battery drain issues.


I would like to relocate the key switch though.  It isn't all that easily accessible where it is.  Maybe somewhere on the side or near the battery box.


My new top triple bridge has no place for one so we'll have to do something regardless.

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I have an 06 150f. I removed the switch when I put cr150r forks on the bike. I bought a trail tech switch, lenghten the two wires and installed switch on handlebars next to the kill switch. I didn't remove kill switch because it has four wires connected to which operates the starter from engages with bike in gear. So i actually have two kill switches. I've been told if you just remove key switch,by connecting them together it will run down the battery.

Edited by dirty mike
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The key switch does only two things and will have absolutely nothing to do with a dead battery.

The switch, when on, allows the start button to work, and when off grounds the the kill switch. 

On the bike wiring harness:

The black/white wire is from the kill switch and the green goes to ground; the ign sw connects them together when off.

The red and black wires are from the start button circuit; and the ign sw connects them together when on.


Like Rick Ramsey I put one on my CRF250X for an additional level of theft protection. It is usually always when on a ride, and only off with the key removed when I feel a need for additional theft protection because it does make the bike impossible to start without rewiring.

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If you look at the wiring diagram you will see that leaving the switch in the ON position will not drain the battery as it is still an open circuit (due to the starter button).  Turning the key simply passes voltage from the battery to one leg of the starter switch.  Only upon pressing the starter button is the circuit completed (assuming there is a ground supplied by either the clutch being pulled in or the bike is in neutral).  Current is then drawn from the battery to energize the coil of the starter relay thereby starting the bike.  Once the starter button is released, it is an open circuit again and there is no current draw.  Therefore, leaving the key on will not drain your battery.


The switch, when on, allows the start button to workicon1.png, and when off grounds the the kill switch.


While it's true that the ignition switch and kill switch share a common connection, the key switch does not ground the kill switch (that wouldn't make any sense).  Rather, the kill switch and keyswitch apply ground to the ICM box (when the kill switch is pressed and/or when the ignition is off), which prevents the ICM from delivering voltage to the ignition coil and subsequently the spark plug.  Killing the engine by hitting the kill switch or by turning off the key does the exact same thing (disables the ICM).

Edited by mossman77
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