EFI switched power source

[fireguyfire]

Just finishing setting up a Holley sniper EFI system in my 73 challenger that has a 70 383 engine in it.
I initially took the switched power source it needs from a free spade connector acc point on the fuse panel, but I quickly realized this won't work as it is not hot during cranking.
The sniper set up needs 12v both switched, as well as cranking.
I know lots of guys are running snipers on E bodies, and I thought I'd check in and see where you guys took your 12 v switched and cranking power from to connect the pink sniper wire to: no point in re inventing the wheel!!

[Skdmark]

 

Looking at ordering a sniper for my 318. Curious to hear what others have done.

[7212Mopar]

If you are still using factory ignition and ballast resistor, then you can run a diode. There are past threads on this including wiring diagrams and diode needed. If you are running after market ignition then you can splice the blue and brown wires for your 12 volt signal.

[7212Mopar]

See if this help.

https://forum.e-bodies.org/engine-transmission-and-rear-end/4/efi-fitech/1959/

[fireguyfire]

Here's my ballast resistor and I have the stock distributor for 73.

[fireguyfire]

I didn't see a diode number so I'll have to dig deeper.
Where would a guy source the diode: auto parts store, or electronics store?

[7212Mopar]

Try PM the member in that post that use the diode setup. I recall he said he got it from Summit. I did not go that route so can't help you on that.

[Scooter]

Had a similar issue a few months back when I upgraded the ignition. I ended up just combining the input from the "start" and "run" leads at the ballast resistor.

[fireguyfire]

Will do; my ballast is wider and has 2 blues going to one side and 2 brown to the other; I'm guessing this is a later version because my car is a 73.
Will 2 wires on each side of the resistor change the way I'll need to set this up?

[Scooter]

Will do; my ballast is wider and has 2 blues going to one side and 2 brown to the other; I'm guessing this is a later version because my car is a 73.
Will 2 wires on each side of the resistor change the way I'll need to set this up?

Mine is a 74 and the ballast only had 2 positions so it was pretty straightforward. I bypassed the ballast as I needed full 12v for the new ignition setup.

What you will need to do is grab a volt-o-meter and find out which is the straight 12v for start and which is the straight 12v going into the ballast for run. Use those 2 combined for the EFI. Hope that makes sense.   

*** EDIT***

Looking at your photo above I'd guess the blue wire is the run and the brown is your start circuit.

[fireguyfire]

That makes sense; just need to add the diode of the full 12 volt brown wire as shown in the attached thread.

[fireguyfire]

Just confirmed on my coloured wiring diagram that the brown comes from the positive side of the coil, and the blue comes from the alternator then through the voltage regulator

[shawge]

  A 1N4001 should be good up to 50 volts.

[fireguyfire]

So I went the recommended route of tying the blue and brown wires from the ballast resistor with a diode on the brown; wired up a mini harness like the one in the attached thread.
Sniper is starting and working perfectly, and I'll take the Challenger for its first EFI rip tomorrow.
Thanks for the help

[Skdmark]

@fireguyfire

Which fuel pump setup did you go with?
I just ordered up my sniper tonight. Putting it on a 318 with LD4B intake.