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Author Topic: More electrical questions - Kill switch  (Read 1588 times)

youngjohn

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More electrical questions - Kill switch
« on: July 26, 2014, 12:09:31 PM »
Am I correct in assuming that the green and green/blue wires from the kill switch/starter connector block should show continuity when the switch is in the central position?

I hate electrics!


Offline Barry

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Re: More electrical questions - Kill switch
« Reply #1 on: July 26, 2014, 12:23:09 PM »
Yes.   The kill switch is in series with the ignition feed so when the switch is up or down it breaks the circuit that provides +12V to the ignition coil.  


Barry Cheshire, England 79 R45

youngjohn

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Re: More electrical questions - Kill switch
« Reply #2 on: July 26, 2014, 12:56:31 PM »
Does it also prevent the starter from spinning when it's in the off position?
« Last Edit: July 26, 2014, 12:57:19 PM by youngjohn »

Offline Barry

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Re: More electrical questions - Kill switch
« Reply #3 on: July 26, 2014, 02:49:58 PM »
Yes.

The kill switch disables the starter relay but I'd have to look at the wiring diagram to figure out how.
Barry Cheshire, England 79 R45

Offline Barry

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Re: More electrical questions - Kill switch
« Reply #4 on: July 26, 2014, 03:04:53 PM »
With the ignition on we have +12v on #15 of the ignition switch - Green wire takes that to the kill switch. Green/blue wire out of the kill switch takes +12V to connector block on it's way to the ignition coil but another blue green wire also loops back to starter button. Blue/yellow wire out of starter button takes +12V to starter relay coil.

So the kill switch is in series with the +12V feed to the starter button and therefore it will disable the starter when the switch is open.
.

« Last Edit: July 26, 2014, 03:08:00 PM by bhodgson »
Barry Cheshire, England 79 R45

youngjohn

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Re: More electrical questions - Kill switch
« Reply #5 on: July 26, 2014, 03:19:07 PM »
Thanks.
I foolishly briefly shorted out the green/blue wire that goes to the rev counter since which the starter won't operate (lights ok). Just trying to find what damage I've done. Hopefully it will be the starter relay. it was a bit clapped anyway so I've ordered a new one.
From what I can see, the fuses don't seem to cover that circuit.

Offline Barry

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Re: More electrical questions - Kill switch
« Reply #6 on: July 26, 2014, 04:44:58 PM »
Quote
From what I can see, the fuses don't seem to cover that circuit.  

That's correct. The Tacho gets it's +12v from the ignition switch and that is fed direct from the battery.  

Shorting the tacho wire would pull a substantial current through the wiring and that would cause some damage if it was more than a momentary short but I don't see how it could damage the starter relay except the relay wouldn't operate while the short persisted. Not that it could persist for long without the wiring going up in flames.

To check if the wiring to the starter relay is still intact check for +12V on #85 of the starter relay when you press the start button.
« Last Edit: July 26, 2014, 04:45:38 PM by bhodgson »
Barry Cheshire, England 79 R45

youngjohn

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Re: More electrical questions - Kill switch
« Reply #7 on: July 26, 2014, 05:59:03 PM »
Looks like it could be the kill switch that's bought it.

Can't find the terminal numbers, but if you look at the relay socket as though you were sat on the bike,  I'm getting a permanent live on the terminal in the holder at 9 o'clock and nothing else.

With the green and green/blue wires from the kill switch connected together I'm getting the permanent live at 9 o'clock plus a switched live at 3 o'clock.