240Z ignition wires

[zercs280zx]

I need to confirm the 12v start and run wires and how to obtain a 12v switched (power in start and run). I have an early 1973 240Z that I'm going to wire in a Crane ignition box and Megasquirt ecu. I've searched the site and I'm pretty sure I have the answer but I'd like to make sure before I solder any wires. I plan to remove the ballast resistor and connect the G/W and B/W wires that were connected to it. I know that this will give me the full 12V in start and run, but I'm wondering if I can run a wire from this point to give me 12V switched (power in start and run) for my ignition box and relays. It seems like it would, I'm just confused how power is distributed to the two G/W wires with the ballast removed. Would this be a good source for 12V switched? Also, I am wiring an electric fan relay that calls for 12V in the Run-only position - - can I pull that from the B/W wire before it hits this junction? If not are there any other good places to pull 12V switched and Run-only?

[vantage]

The wiring diagram indicates that either b/w or g/w is life depending on the key position, but when i checked both wires on my '72 240Z it turned out that b/w is life in both ignition on and start key position.

 

You should not put a heavy load on the b/w wire though, as it is directly wired to the ignition key with no relay inbetween. So for my Megajolt setup, i'll use the b/w wire to activate a Bosch 0 332 019 151 SPDT relay via terminal 85, terminal 86 is wired to ground. Terminal 30 (input) of the SPDT switch is connected to battery (+) vi a fuse, the two output terminals (both are labeled 87) are then wired to the Megajolt controller and the coilpack.

 

You could run the fan from the relay described above too, and switch the fan supply off via the g/w wire by using an additional, inverse relay (this type is an closed switch when deactivated). Keep in mind that the fan will start running as soon as you switch to the ignition position, even if the engine is not running yet.