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so i have a 6 pole kill switch for my car, and only disconnecting the battery positive doesn't kill the engine, it keeps running.
according to diagram below, do i just ground out the positive cable with a resistor, which is connected to the alternator. would that work?
NB Miata alternator diagram (attached) is identical to the RX8 so I infer that it is computer controlled. I posted the RX8 diagram because the wire colors are listed. Here's how it was explained to me for the NB (I've change the wire descriptors to make it correct for the RX8), take it or leave it.
The W/G wire is the signal wire to the PCM. It is connected to one of the three stators so it senses whether or not the alternator is turning. The BR/R wire is the signal wire from the PCM to the exciter. If the alternator stops turning, there are no pulses on the W/G wire so the PCM cuts signal to the BR/R wire disabling the exciter and turns on the ALT warning light (presumably).
So cutting the W/G wire triggers the PCM to disable the internal exciter and charging stops.
Now I'm going to have to disconnect this wire on my car to prove the theory.
The W/G alternator wire works for my switch.
So all our previous theory is incorrect apparently. I'll verify that battery positive alone doesn't kill the car next weekend.
So all our previous theory is incorrect apparently. I'll verify that battery positive alone doesn't kill the car next weekend.
i PM mr.pockets yesterday and he tired his kill switch which only disconnect battery positive while engine is running and the engine stays running. That's two case that has proven it. no need for you to go through the trouble to try it.
so if i disconnect the W/G wire, and battery positive, that would kill the engine, correct?
so according the the wiring diagram i posed above, do i bypass the W/G wire to the Z connector on the kill switch?
do i also wire the ground wire with resistor to the kill switch W connector and to the battery positive. i guess that's for surge protection?
Even if you kill Bat+ the running engine will still receive power from the alternator because the Alt+ wire attaches right at the Bat+ post terminal. You would need to have the disconnect between both of those wires and the battery post to kill it that way instead.
if that's the case, you'd have to run a larger gauge wire from Alt+ to the cut off inside the car. it would be easier to run smaller gauge wire from cut off to the w/g wire on the alternator.
if that's the case, you'd have to run a larger gauge wire from Alt+ to the cut off inside the car. it would be easier to run smaller gauge wire from cut off to the w/g wire on the alternator.
if that's the case, you'd have to run a larger gauge wire from Alt+ to the cut off inside the car. it would be easier to run smaller gauge wire from cut off to the w/g wire on the alternator.
I just tried this. It didn’t work. Car still runs when the switch is turned off.
Okay, in that very first picture on this thread I can tell the br/r wire is the one that's switched. I ran that through the master switch, and now the car shuts off.
Conclusion: I have no idea why it works, but switching the br/r wire and the positive battery cable kills the car.
So I finally wired the alternator cut off last night. Looks like the w/g wire didn't kill the engine for me. The other wire did. The kill switch will cut all power and kill the engine now while it's running.
I was doing some electrical work on the car today and decided to investigate this further. My car dies when the kill switch is thrown whether or not the W/G wire is connected. This is because I have a very large alternator pulley and the alternator doesn't charge until around $4k RPM.
I didn't try throwing the switch at 5K out of respect for the neighbors.
For anyone reading this thread, go with the known, BR/R.
haha, why not go with under drive crank pulley. i just got one that i need to install. hoping to slow down the water pump and reduced chance of cavitation
haha, why not go with under drive crank pulley. i just got one that i need to install. hoping to slow down the water pump and reduced chance of cavitation
Got that too (BlackHalo crank and water pump) so the alternator is spinning really slowly.
So I finally wired the alternator cut off last night. Looks like the w/g wire didn't kill the engine for me. The other wire did. The kill switch will cut all power and kill the engine now while it's running.
@trackjunkie
If I'm understanding this correctly, one needs to cut that brownish/orange wire at the blue alternator plug and run a length of 2 wires to/from a post on the kill switch. Is that right?
Along with the battery of course.
Alternatively, I understand one can interrupt the main ignition relay in the fuse box via the blue wire instead of the alternator.
Thanks.
