Author Topic: Black Box V2 kill switch issue  (Read 1207 times)

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Offline CbBrat550

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Black Box V2 kill switch issue
« on: September 22, 2021, 03:45:26 PM »
Hey guys, I am having some trouble trying to install this Black Box v2 control unit by Purpose Built Moto on my 1978 CB550. Everything is going smoothly setting up all of my push button switches for light, turn signals, and the starter button, but the only one I am having trouble with is the kill switch set up. Being that the old kill switch with the old wiring harness has the black and white wire with a black wire, and toggles the open connection between getting power to the coils. The suggested wiring diagrams given show how to function on the positive and ground side of the circuit. The push button for the kill switch in both of these cases have a powered wire and ground wire.
Is this the correct way I should be trying to wire the bike for a kill switch?

I have currently tried both diagram set ups, but might be missing something. The way I have it set up is that the RLY2 wire is going to the black and white wire at the coils, the RLY1 going to a ground, and the RLYsw going to the push button.

I have been trying to check if the coils are getting power when the button is pressed or not and don't seem to be getting any change in continuity .

Any suggestions would be great! Thanks!
« Last Edit: September 22, 2021, 03:50:28 PM by CbBrat550 »

Offline calj737

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Re: Black Box V2 kill switch issue
« Reply #1 on: September 22, 2021, 09:43:30 PM »
According to their documentation, power is fed directly without pressing the button. Pressing the button interrupts power to the ignition circuit, but only while depressed.

So with key ON, you should have 12v to the coil. If not, resolve that first (make certain you ground the coils to the frame via the mounting bracket).

Once 12v to coils is solved, then you deal with “disruption” via the push buttons.

**** On a personal note, I think this is a TERRIBLE design if I understand their documentation clearly. The KILL switch only disrupts power while depressed. So you running along, need to kill the motor in an emergency, press the button, motor stops. You let go of the button, what insures the motor doesn’t restart? Simply that the starter solenoid isn’t excited? Hmmmm…. Makes me nervous to think about the possibilities.

Push button KILL switches as a stand-alone control are not great. A toggle/rocker type would be far more prudent. Flip it and power is disconnected. Flip opposite, power is now available. It’s a more static condition. And how can you rely upon a stranger who may come upon you after an accident, bike running, and they not immediately see how to kill the motor? Just saying… You might want to give that a bit more thought. ******

But your wire schema sounds correct per their diagram, just confirm power as described above.
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Offline CbBrat550

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Re: Black Box V2 kill switch issue
« Reply #2 on: September 23, 2021, 10:46:18 AM »
Hm, I see what you mean!! That is a terrible design honestly  ???  ??? in that case... I honestly will probably get another switch, such as one you are mentioning that mimics the old toggle design, and use that particular push button for something else... I guess that's what I get for trying the cheaper version of an M-Unit!!  ::)

I appreciate the quick response !! I will try this and see if that works. I am still fairly new to rebuilding/restoring these bikes so any information helps a ton!!  :D

Thanks!