12v ign source

[lasvegas69charg]

Is there a 12v ign source that will stay HOT during cranking in the bulkhead that I could tap on the engine side? My ballast has been modified with a solid wire(looks like original but it's straight thru for my msd ready to run) Could I tap off of that?

[Nacho-RT74]

 the wire going to + lead of coil is hot in RUN and Cranking. being a 69 is blue ( since 70 become in brown )

Coming from bulkhead connector ( before the ballast ) there are two wires, Blue and Brown, which are the ones what feeds the ballast. Straight from Ign switch, the blue is 12 volts hot in RUN, brown is death, and Cranking the Brown one is the one which gets full 12V and blue is death.

When both are connected to the ballast, both are hot in both stages but with diff voltage rates due the power being spliced into the ballast, but FROM IGN SWITCH, is what I exposed.

to get full 12 volts in both stages ( mod usually made to hook aftermarket ign systems, although not necesarry in all setups ) need to splice both blue and brown wires coming from bulkhead ( before the ballast ).

HOWEVER, MSD modules for example, opposite to what ppl thinks and have done allong the years DOESN'T NEED to bypass/remove the ballast and splice both wires together since it needs this signal JUST FOR TRIGGER IT on and off. Coil wire coming from ballast is enough for that. MSD modules gets the full power straight from batt with the thicker red wire. Diff story is what ppl preffers to do ( remove ballast and splice wires, or not )

[lasvegas69charg]

Ok. Got it.  thanks nacho

[John_Kunkel]

HOWEVER, MSD modules for example, opposite to what ppl thinks and have done allong the years DOESN'T NEED to bypass/remove the ballast and splice both wires together since it needs this signal JUST FOR TRIGGER IT on and off. Coil wire coming from ballast is enough for that. MSD modules gets the full power straight from batt with the thicker red wire.

That might be true but some would question the wisdom of tapping off of the coil wire to trigger the MSD...IOW, how much current does the MSD draw and how does it affect the coil operation?

Since the OP has a modified straight-through ballast, the point is moot in his case.

[lasvegas69charg]

So is it ok to tap off the wire at the ballast going to the coil as my trigger signal to my msd atomic efi? The msd atomic also has a direct connect to the battery.

[John_Kunkel]

I wouldn't use the coil wire as a trigger for anything, there are other keyed sources that are better. IMO the blue wire on the voltage regulator is the best source for keyed power.

[Nacho-RT74]

newer MSD module manuals state the coil wire use for that, instead cut and splice. ( IN FACT, states explicity on Chrysler diagram, FROM ORIGINAL COIL + TERMINAL, although on wire color code table says 12 volts source ). Can't talk about EFI systems but I wouldn't think being different. Manual code color wires states the same than modules though.

Blue wire on regulator without a ballast connected or ballast wires spliced won't have power while cranking

[Nacho-RT74]

NOTE:
I allways have talked about the ORIGINAL + coil wire. Never from + lead of coil when using multispark systems.

Ready to run dist can get in fact ( by what diagram shows ) the power also from + lead of coil without say a ballast bypass being required. weird, because on these, THIS wire becomes on a source too, not just an on/off trigger