Sorry to start another thread on this topic gentlemen, but for all who are researching what/how/where, this is a straight forward, on topic post/thread.

As you probably know, the factory used a pink resistor wire from the ignition switch to power the coil. This reduced the running coil voltage to around 9 volts. The purpose of doing so was that old time points could not handle the higher voltage and would burn up if full voltage was ran. But with many of us getting away from points and going to an electronic ignition, (pertonix, HEI etc.) this is no longer required and hinders spark performance. The way to improve this is simple, run full battery voltage to the coil.

Depending on your personal situation and setup, there are 2 common ways to do this.

1: use the existing wire to trip a relay hooked to a full voltage source

2: bypass the pink wire from the switch and run a new, regular wire, from the switch to the coil.

I chose option 2 because it was clean and simple. No components to add. Which I believe, less components=more reliable.

SO, first things first you want to remove the ignition switch from the dash. This just makes it easier all around. This is done with a punch or screwdriver in the 3 little slots around the key. Lightly tap the ring around counter-clockwise until it's loose enough to use your fingers. Take the ring out and push the switch out. Let it hang

The plug to the back of the switch is probably on tight, so just work it off. Wiggle it while pulling firmly. It will come apart. Now you can see the connectors.
Now on my truck, there was a light blue wire sharing the same terminal as the pink wire. My wiring diagram says that it controls something called the "throttle solenoid". Whatever that is, I didn't have one to worry about. So that wire didn't matter.
I'm not sure how exactly the connectors are held in the plastic, but I was able to work it out with an 1/8" pocket screwdriver and some finagling.

Now route your new wire. I used a red 14ga copper wire. You can poke a hole in the side of the same sealed grommet that the other wires go through. Get it out to the coil and leave enough slack for future adjustments/fixes. And get it back to the switch with some slack.

I had the right size connector on hand, so I opted to use a new connector on the new wire and leave the old pink and blue wires intact. If you don't have the right connector you may need to reuse the old one.

Right behind the firewall, in the wrapped wire loom, there is a brown wire from the starter solenoid. You need to clip that wire and tap the solenoid end into your new power wire. This is essential to operation as the brown wire is what provides coil power when cranking.

Hook up your new wire to the switch, then the coil, and give it a shot at starting. If it starts, you did it right. If not, go back and check what you missed.

Now that you have full voltage and stronger spark, you can increase your plug gap if you so desire. I opened my plugs to .045" gap.

Put everything back together and your done.

Now, since I've done this mod on my truck, I've noticed a difference. It starts about the same, but idles smoother right off the bat, has more power and is smoother when cruising, and I believe I have gained a few MPG's. So it is working well for me...

If I missed something or it is unclear, ask and I will try to explain it better.

 

Great write up!

I used the pink wire to power my HEI distributor because the module can operate from 4VDC to 24VDC. I didn't think there would be any difference supplying it with 12VDC rather than the 9VDC.

I have a way to measure at least the peak spark voltage, and maybe even capture an entire waveform. When I get some more time I'll try doing it both ways and post the results.

 

I used the power wire from the old TRS to power my Duraspark/MSD ignition.
FWIW, Pertronix doesn't need a full 12V to operate and the stock resistor wire is sufficient.

 

Indeed the pink wire is sufficient and the pertronix module doesn't need it, however i did it more for maximum spark output. I have a high performance coil, so feeding it only 9 volts kinda defeats the purpose. And I feel better knowing that full voltage is going where it it supposed to be.

 

I've been on a rampage of digging up OLD threads here lately. For the past couple of years, I've been so dawg gawn busy. I still am, but I have found time to hang with my friends.
That I am a wiring idiot and dislike auto wiring as much as I dislike house plumbing, I'm a little dense.
Blue and pink wires get removed from iggy switch connector and "abandoned", new wire in the "home" of the anandoned blue/pink wire, new wire from iggy switch to coil and "T" in brown wire. Correct?

 

Correct-a-mundo Chris.

 

You got it

 

Great write-up! Just as an FYI to anyone reading the thread later or looking at a wiring diagram. I also share the blue wire with the pink one on my switch connector. I believe the throttle solenoid was used on the carburetor (optional on these trucks, I THINK) to bump the idle up a bit as the temperature of the engine rises. Thus flowing more coolant and cooling the engine back down. Mounted on the front of the carb with a plunger that pushed the accelerator arm up just enough. I can't say for sure but I think it was activated by a vacuum operated thermactor thingy in the thermostat housing that is usually plugged off. Anyhoo I may be all wrong on this, just a thought. It may have been there to raise the RPM on A/C equipped trucks also. When the A/C was turned on

Dan

 

Same colors on a 69?

speaking of digging up old threads, Jefffafa. Do you have a magic decider vin tag ring for 69's? Saw one on a 72 from way back yonder...

 

The following comments are mostly for beginners, and those saving money. Read this if you don't have a racing coil.

You don't need a racing coil. You have to run your truck for HOURS, not minutes. The voltage only goes up to around 16,000 volts, and jumps the spark plug gap. Only when you have fouled plugs, way-to-lean mixture, and other sins would you get any value from one. Racing advice causes some problems you don't want to pay for. Although, ... it may cover up other mistakes ... for a while.

The Pertronics modules come in a couple of types, with the older ones preferring less voltage. They are all great and highly recommended. All may be run on the "pink wire" and work just fine. You will get more benefit from this one mod, than nearly anything else. Even if you're poor, consider it. It will pay for itself in a couple of years.

The "brown wire" is almost full battery voltage to the coil, and is needed for Starting. Think of it as a temporary by-pass to the cold battery. If yours is missing, add it. Since the battery is 12.2 - 12.6 Volts at best, and drops greatly when cranking, you might only have 7-8v in cold weather. So, you want the lowest resistance possible for a few seconds. The brown wire connects to the "I" (Ignition) terminal. Wire from the "Start" terminal on the ignition switch goes to the "S" (start) terminal on the solenoid. (Thanks JAFFFAFA. And if this is confusing see Mad_Mike: https://www.ford-trucks.com/forums/1...l#post17089836)

Once the engine starts, the voltage in the system goes up to as much as 14.8 volts, then drops with increasing temperature to 13.2v. This running voltage may overheat a normal coil, and especially causes trouble in warm weather. ( Notice how many people get a "bad coil"? Hmmmm....)

So, after the crank-and-start cycle, the juice flows only through the "pink wire" to reduce it back down to something that won't heat up the coil (and in the old days, burn the points up quickly).

If you live in Alaska, or up north, you don't care. Direct 12v might work great. The "blue wire" that may have gone to a fast-idle solenoid can be used. It is found in the same wire bundle as the "pink wire" It is a little lower in volts than the battery, as it is a long run of light wire, and has some connection resistance.

If you are a racer, or have a lot of money, you aren't supposed to be reading this.

If you are attempting to hyper-mile, or run your mixture Very lean, then 'maybe' a racer's coil is for you, and you want 13+ volts going through it. But that is tough on valves, creates oxides of nitrogen, and makes the engine run really hot.

Your voltage may vary.

(Commentors: I replaced all of this wiring, and may have forgotten what it looked like originally, so correct me if wrong in a PM, and I'll edit.)

 

I need pictures. Good instructions but I got lost with what to do with the original pink and blue wires? Do you just get rid of them?

 

Todd,
The hot rodding kid 351 sounds like he just left it in the loom an foiled it back an taped it in place if ever needed to reuse it again.

Ps in his write up to me it's easier to remove the dash cluster and work through that opening.

I did not have the little special plug connector had to order it.
I needed my truck running sooner then 4 days so, I went to the loco PnP JY an got me a pink wire from a GM truck ign. switch as it has a #10 ga. wire that did the job an would take like 4days waiting on that little connector to come in.

Orich

 

OK, help me here. There was some other deal about the Pertronix I (maybe??) getting damaged if the switch was left in the "ON" position. What was that? My memory is pretty bad, but I remember something along those lines. I may be way off here. If someone doesn't know, I'll try to research it a little when I get home this evening....

 

If the ignition switch is left in the ON position for several minutes/hours (without the engine running) an Ignitor 1 may be damaged. Later Pertronix Ignitors have protection circuitry to prevent this.

The ignition Coil will roast in this situation as well, and start to leak, and may go off, spewing oil and wire.

Points and condenser has the same issue btw. If the points happen to be closed in this scenario, the current will flow and roast the contacts and coil.

 

This thread is getting more attention now than it did when I wrote it almost 3 years ago.... amazing.