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Since Red w/green was the color for the ignition coil wire only (as far as I know for a '68 anyway) it's very likely it was part of the wire from the factory.
Have not been behind many dashes of the pickups, but the Broncos were done in different ways over the years.
On some, the Red w/green wire would come out of the switch to a small push-connector, where it transitioned to the resistor wire for most of the rest of the way to the firewall.
On others, the resistor wire was routed all the way to the ignition switch in one piece, with no connector to allow you to easily change out a burned up resistor wire.
I've seen variations too, where both wires were spliced to the same contact point on the switch. This was mostly on later trucks with electronic ignitions I think. Where the resistor wire ran to the ignition coil as always, and the new Red w/green wire powered up the Dura Spark ignition module. Along with a few other keyed items too, for some vehicles.
Probably other variations as well, but not sure.
In other words too, I'm not sure how yours was wired originally, but both colors are legit for your year. How they were originally connected at the switch is the question. Others that have fiddled with their switches more recently will know though.
Since Red w/green was the color for the ignition coil wire only (as far as I know for a '68 anyway) it's very likely it was part of the wire from the factory.
Have not been behind many dashes of the pickups, but the Broncos were done in different ways over the years.
On some, the Red w/green wire would come out of the switch to a small push-connector, where it transitioned to the resistor wire for most of the rest of the way to the firewall.
On others, the resistor wire was routed all the way to the ignition switch in one piece, with no connector to allow you to easily change out a burned up resistor wire.
I've seen variations too, where both wires were spliced to the same contact point on the switch. This was mostly on later trucks with electronic ignitions I think. Where the resistor wire ran to the ignition coil as always, and the new Red w/green wire powered up the Dura Spark ignition module. Along with a few other keyed items too, for some vehicles.
Probably other variations as well, but not sure.
In other words too, I'm not sure how yours was wired originally, but both colors are legit for your year. How they were originally connected at the switch is the question. Others that have fiddled with their switches more recently will know though.
Paul
I read somewhere that in 67-68 the factory ignition switch was hardwired into the harness and had a bad habit of catching on fire. Apparently, there was a recall (or whatever a recall was called in those days) where the factory harness was spliced into the new pigtail and ignition switch that most trucks have now. The 68 wiring diagram shows the pink wire going from the connector plug (the plug that connects the ignition, water, and oil wires from the motor to the harness) into the red w/green wire, with the red w/green going into the ignition switch. My guess is that on my truck the recall pigtail harness was put in but that the pink wire was wired directly to the ignition switch plug and not into the red w/green wire.
Anyway, it's fun solving 50 year old wiring mysteries!
...the resistor was there only to create a hotter spark ...they know way more than I do about electrical theory. And even one of the descriptions in the Ford book for '79 said something quite similar. Unfortunately, none of them (members nor Ford) really explained it in any clear language.
I think maybe "they" are talking out their third point of contact. The ballast or resistor wire is bypassed during START, this increases spark intensity. Points will burn rapidly without it though, if run on a continuous basis. More voltage at the coil primary means a higher voltage at the secondary. Hotter spark at the plugs. But, this also means more current through the primary circuit. They had to limit the current, this is done by a separate ballast resistor.
It may be what you're actually referring to is resistance type noise suppression plug wires, these result in a higher coil firing voltage. That's what it sounds like anyway. I can't really comment on what a book from 1979 may or may not have said without specifics. Maybe scan a pic of a paragraph or two and get it sorted out.
Again, would love to have that equation ready to hand when figuring out the proper ignition components for someone. What actually determines the amperage drawn through an ignition system like these? How do you figure it out without their data listed? Do you use a generalization and take their claimed voltage output of, for example, "45,000 volts" and do some math? Or do you have to ask them?
Or can it be figured out with other information based on your own particular components?
Just wondering how you figure out if your system is going to allow your trigger mechanism to see 3, 5, 8, or 10 amps.
Sure. But what does that indicate when you run the numbers? Just that 12v (or 14.5v while running) divided by 1.5 ohms equals the actual current that is flowing through the Ignitor components?
Seems like there would be more to it. Such as how much the unit itself "uses" or "blocks" by way of adding it's own resistance perhaps? Maybe as an electronic device that loss is minimal, so we're still looking at 9-ish amps flowing through the Ignitor with a 1.5 ohm coil?
Didn't think it was that simple, which is why I asked the previous questions. I'm aware of ohm's law, just didn't think it applied directly as-is in this case.
That's pretty much all there is to it. The ignition primary circuit is the sum total of the the coil windings and the associated wiring. I'm not very good at schematics but a standard ignition circuit is almost within my skill set. It really helps to get in the manuals and shop publications, they explain everything and break it down by isolating systems into blocks. The resistance in the primary circuit has to be in a certain range. Too high is no good either.
Grounding is really important. There are basic troubleshooting steps with a simple voltmeter where defects in corroded connections can be found easily, these will inhibit a good hot spark at the plugs in ways that are otherwise tough to diagnose. It's one thing to get a plug to spark in the open air but a totally different thing under high cylinder compression, a heavy load and high RPM. Even a defective ignition switch can cause all kinds of trouble or a poor distributor ground, and solenoids can fail in the primary too.
One thing that complicates the amps calculation a little bit is the coil is not "On" all the time so the current is actually somewhat less than Ohm's Law would indicate. For V8 the dwell is somewhere around 30° or about a 67% duty cycle. This is why leaving the key in the ON position without the engine running will tend to burn up and lunch the ignition coil after several minutes. Too much current flow. I use 14 or 14.5 volts as a baseline, something like that, not 12.6 nominal battery voltage.
I like to try and understand the "why" and "what" behind otherwise sometimes cryptic specs and instructions. Study the manuals and get a handle on what's really going on and you can usually make your own informed decisions without depending on thirdhand speculation and wankery.
The wire that the PO spliced into the pink wire was red with a green stripe. I'm still trying to figure out what it goes to, I haven't traced it back. My 68 wiring diagram doesn't help either. Do you think it my red w/green stripe used to be attached to the pink wire further back? See pic below.
The burned up red wire w/green stripe was the keyed 12 wire that goes to the voltage regulator.
It's possible, but if they're consistent in wiring colors like they've been for these three colors, the voltage regulators are always Green w/red stripe and the ignition duties are always Red w/green stripe.
When electronic ignitions were introduced, the wire color stayed the same, but split off to power not only the coil, as in previous years, but the ignition modules and a few other things as well.
And yes, on older trucks the "method" changed, but the colors should have been consistent. Some years the Red w/green exited the ignition switch for a few inches, then became the Pink wire. Others the Pink ran right down to the switch connector directly.
Some of the spliced ones were one wire, while others had connectors so you could literally change out a failed resistor wire with little fuss. I went down to my local Kragen store (now O'Reilley's) and purchased a Standard Motor Products replacement Ford resistor wire that had that bullet connector. Ford dealer had one as well, but I don't think I have one. Still have the Standard one in a box somewhere because it turned out that I didn't need it after all.
So the wiring does vary by year, but the wire colors should be the same. Hopefully your Red w/green wire runs up to the ignition.
On most older Ford Ignition switches, the Green w/red and the Red w/green are the only two wires that are hot only with the key in the ON position. Whereas all the others (except for the Red w/blue) are hot in ACC and ON both.
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