Any ideas on how to get a 12v source while cranking (starting) the engine? All my switched 12v sources drop power when I am starting the engine. ???
What are you trying to power with this source?? The wire that activates the solenoid should have this power as well as the positive side of the coil, assuming your battery will supply it, while under cranking load.
Couldn't you use a 2nd solenoid, use the feed that drops power to activate the 2nd solenoid that is a direct feed from your battery to what you are trying to power.
Man I should have taken notes, There is 1 wire coming off my steering column switch or the back of the fuse block on my 74 that I used but it took awhile to find it. (I just looked and I can't even figure out what I did) I used a test light and disconnected the starter solenoid to keep the engine from turning over, probe each wire until you find the one that stays on, I also used a relay switch to take the load instead of directly connecting my ECU to the 12v source not knowing how much amps it would take.
Quote from: fast34 on March 13, 2006, 09:53:50 PM
What are you trying to power with this source?? The wire that activates the solenoid should have this power as well as the positive side of the coil, assuming your battery will supply it, while under cranking load.
Some ignitions use 6 volts to the coil with a resister built in somewhere in the wiring, it won't hit 12 until you crank the engine, the wire I found was before the resister.
The MSD 6a requires 12v ignition source, other than Battery, that is also on during the start cycle. MSD tech says not to hook to alternator. I'm thinking a relay that is triggered by the 1 wire alt.
So does the factory ford duraspark module, and it uses the wire that triggers the starter solenoid. If this is what you are worried about, quit worrying, all that wire does is tell the box to change the timing a little to make it easier to start. It doesn't matter if this voltage drops a little, I dont care where you pull your juice from, when you crank that starter the whole system is going to drop.