CDI wiring help

[rodneya]

I am busy wiring in a banshee CDI to whats left of my RD350 harness.
In the wiring diagram it looks like the red/black wire from the CDI to the ignition switch just goes to ground when the key is on. Is that correct?

Also can I wire the black/white wire from the CDI straight to my RD kill switch or do I have to go through a relay like my vape system?

Did I mention that I dont like wiring.

[1976RD400C]

According to your diagram, the red/black does need to be grounded to run but the stock kill switch is hot 12 volts and you cant connect the black/white from cdi to that. You need the relay to isolate it and a separate circuit in the relay will ground it for shut down.

[m in sc]

yup.

a 5 wire relay will be your friend here.

so if you look below,  there's 5 pins. 85 and 86 are - and + (switched) power. this gets powered by the kill switch if you have a battery. so on = active.

30 is your signal. in your case, this will be connected to frame ground.

87A is 'normally closed'. this is what makes contact when the power is not on (12v). you would leave this empty.

87 is 'normally open'. this only gets power when 12v is applied to the relay.

I would think that you can use this (pin 87) to connect the black/red wire if ground is required for it to run. that way, 12v applied grounds the pin. key or kill off, relay un-grounds the box and it stops. 

this is a standard automotive accessory relay, any chain store will have one cheap, on the electrical aisle.


as a side note, IF you were using a relay to ground the kill wire on a coil, such as on an mzb or vape, you would wire it exactly the same except you would use pin 87A to the kill wire off the coil, or cdi box if applicable, and leave 87 open.

you can also use a relay to interrupt the signal from the pickup as an effective way to act as a kill switch.

[rodneya]

Thanks, I was looking at 4 pin relays trying to figure out the kill wiring.

[m in sc]

you can use a 4 pin if its normally open. 

[1976RD400C]

It seems to me you can use one 5 pin relay to accomplish both circuits. Connect as m in sc describes using just the one relay.
  85 ground
  86 ignition switch
  30 ground
  87  red/black wire
  87a   black/white

  When the relay is not energized the black/white kill wire is grounded shutting down motor.
  When the relay is energize, to start bike, the black/white becomes open and not grounded. The red/black becomes grounded as need in
  your schematic.

[Dvsrd]

you can also use a relay to interrupt the signal from the pickup as an effective way to act as a kill switch.

I wonder if that may harm the cdi box. As it still receives juice from the energizer coil, but cannot discharge ?

[m in sc]

ive done it, never had an issue.  the likelihood of the motor stopping right at the trigger to discharge everytime is pretty slim as well. just fyi. BUT,  Ialways -prefer- a kill at the box or the coil if available.

[rodneya]

I now have spark and a working kill switch.
Thanks for the help Mark.

Kinda nice to know that the stator, flywheel, coil and CDI that I got off Facebook and eBay actually do work