Another thread revival.
So a friend and I (he’s finishing up his SE30 car) decided to go the solenoid route for a master switch. Trying to finalize the wiring.
Cutting the main 2/0ga battery cable is a no-brainer. But, this thread seems to insist that the 2 wires running from the positive terminal of the battery have to be disconnected from the battery and each other. This makes sense since the small wire can supply power from the alternator to the DME.
My friend, however, went a different way. Not sure if he found this online, or came to this conclusion based on the troubles he was having trying to cut the OBC out of the wiring harness, but instead of cutting the power to the DME from the alternator, he instead cut the green power running to the DME from the OBC relay box.
It seems to have the intended effect – shutting off the car. Also, it’s a smaller wire that doesn’t need a beefy switch (though it is further away from the rest of the action). I’m planning on running a few remote cutoff switches in the car – one aircraft switch near the driver’s A-piller (probably coming out of the vent, next to a fire pull), one on the center dash next to the other switches, and one large push button switch on the main hoop by the passenger window. I’m considering following his lead.
Just wondering if there’s any fault in the “kill” logic here. It’s hard to determine from the ETM what the green wire does for the ECU. It just says it goes to pin 27. The black wire off the battery junction goes to, effectively, 3 pins marked as “power inputs”. But if cutting power to pin 27 shuts down the ECU and kills the motor, isn’t that sufficient? Any situation where this would fail to kill the engine?
Oh, and here’s a schematic I drew–I mean–uh… conveyed to a 4 year old… who drew it on a computer.
(for me, the GN wire would go to the ignition/run switch, but it would go to the OBC relay in an unmolested car)