Help wiring Pertronix 3 distributor

[YellowHorse]

Instead of high jacking threads of others I am making one that's dedicated to my issue and questions.

Bought a car few weeks ago with upgraded Pertronix 3 distributor.

Curent wiring situation is as folows:
1. Coil is wired backwards - negative side of the coil has stock pink and green I wire and Ignitor red wire. While Neg. side of the coil has Ignitor black wire.

2. Coil is 0.6 Ohm. I believe Ignator 3 need 0.32 OHm - maybe bad for stock tachometer

3. Voltage feed to the coil is stock 9V while running. No attempt to run 12v feed was made. Last ownder only added a killswitch between coil and Pertronix as theft prevention (found switch under the seat), which confused me with wiring.

4. Car is still using stock Tachometer which makes this matter complicated.

...... Questions to be answered:
1. Any reason why someone would reverse polarity of a coil?

2. Is there a way to wire Pertronix ignitor 3 without feeding or back feeding 12v to the tachometer? A relay or diode to prevent tech seing anything abnormal?

3. If power from tachometer feeding coil, how does tachometer gets feedback?

 

[midlife]

Factory tach is a current-sensing device, and the negative side of the coil is almost but not quite the ground point. I could see the tach working (how well or accurate is another thing altogether) the way it is wired, but it is not correct by any means.
You need to contact Pertronix and see if they offer an adapter for Ford inline tachs.

 

[YellowHorse]

Petronix just telling me to use Ignitor 1...while we know Ignitor 2 works just as well.

Baced on 12v bypass diagram, those who feed coil 12V still hook up resistor wire to the coil where 12V is connected. So my take on it is that there must be a back feed back into resistor wire.

Not sure how coil resistance have impact on the tachometer ??? But read somewhere that potentiometer (0.5 wat, 50k) can work to dial in correct rpm when spliced in between coil and resistor wire.

 

[Ryunker]

I am ready to do the "3" thing in my '71, coil distributor upgrade and their wires. I will be bypassing the factory tach, running 12v from the throttle solenoid wire to power the ignition as carb is not oem.

Will be sending oe tach to get modified so it can work.

 

[Hemikiller]

Follow what Ryunker is doing, use the Red w/Yellow hash mark Throttle Position Solenoid feed wire to power the Pertronix module by itself. Red w/Yellow has is fed through the 14A #6 fuse, and is backfed from the "I" terminal on the starter solenoid in the "Start" position. Move the factory red w/green stripe wire to the coil (+) and the Pertronix black wire onto the coil (-).

Everyone assumes or assumed (myself included) that the Pertronix is a "no modification" upgrade in a Ford, and it's not. The original instructions were very poorly written and caused this confusion. The newer revision is better, but still can be confusing. The key piece of information is the "Figure 3" diagram that shows the power for the red module wire *before* the ballast resistor or resistor wire. There is mention of doing a voltage check after installation, but best practice is to simply feed it 12V from the get go.

 

[YellowHorse]

Follow what Ryunker is doing, use the Red w/Yellow hash mark Throttle Position Solenoid feed wire to power the Pertronix module by itself. Red w/Yellow has is fed through the 14A #6 fuse, and is backfed from the "I" terminal on the starter solenoid in the "Start" position. Move the factory red w/green stripe wire to the coil (+) and the Pertronix black wire onto the coil (-).

Everyone assumes or assumed (myself included) that the Pertronix is a "no modification" upgrade in a Ford, and it's not. The original instructions were very poorly written and caused this confusion. The newer revision is better, but still can be confusing. The key piece of information is the "Figure 3" diagram that shows the power for the red module wire *before* the ballast resistor or resistor wire. There is mention of doing a voltage check after installation, but best practice is to simply feed it 12V from the get go. I actually bought



View attachment 67760

Thanks for your input. Do you think it's too much to use Throttle Position Solenoid power to ignition and electric choke?

Other option is to to take power from before it feeds tachometer ( same line that goes through tachometer and becomes resistor wire). Unless tachometer will sense voltage drop.
I actually bought extension lead harnesses to grab power prior to tachometer and then paused because I noticed that diagram (which I posted above ) indicated that it will not work for Ignitor3 - it indicates to pull 12v wire to the coil.

 

[midlife]

12V is going to the tach, so you can take power from there.

 

[tpj71mach]

Thanks for your input. Do you think it's too much to use Throttle Position Solenoid power to ignition and electric choke?

Other option is to to take power from before it feeds tachometer ( same line that goes through tachometer and becomes resistor wire). Unless tachometer will sense voltage drop.
I actually bought extension lead harnesses to grab power prior to tachometer and then paused because I noticed that diagram (which I posted above ) indicated that it will not work for Ignitor3 - it indicates to pull 12v wire to the coil.
View attachment 67783

Sorry if this has been answered and I can't see the answer but can you use the 12V red for the solenoid to power the distributor and the choke or do I need to run a separate switched 12V for the choke? Also I used my meter and the red/black for the coil measures out as a full 12 volts with the ignition in run position, shouldn't it be a lower voltage due to resistor in the wire?

 

[midlife]

Sorry if this has been answered and I can't see the answer but can you use the 12V red for the solenoid to power the distributor and the choke or do I need to run a separate switched 12V for the choke? Also I used my meter and the red/black for the coil measures out as a full 12 volts with the ignition in run position, shouldn't it be a lower voltage due to resistor in the wire?

Best to use a line from the STATOR post on the alternator to power the electric choke: that's what Ford did. It has about 6V, so the choke will only come on when the engine is running and open slower than a full 12V.
If you measure voltage at coil without the engine running, there will be no current flowing and you'll see full voltage (no load on the circuit). You'll only see lower voltage when the engine is running.

 

[Stanglover]

Well, I'm late to this party, but I have a passionate hatred for the P III. Personally I wouldn't recommend or use one UNLESS Pertronix have redesigned the "bearing" between the two plate on the Ford version. I had this problem when my engine was rebuilt in 2012 and the builder took it upon himself to put a PIII in. It caused nothing but problems and with it on a distributor machine, it was clear that the plastic bearing had failed. I sent it back to Pertronix who replaced it with a P II and coil, but offered no explanation. I've run a P II since with no problems (other than a second one I got was a dud right out of the box).
Before I even ran that motor in my car, I cut out and bypassed the pink resistor wire with a 12 gauge wire as suggested in the instructions for the P III. I later found that all I needed to do was run a relay for it directly, which would have been far simpler.
If it's of any help, here is also a pfd of the MSD tack adaptor

 

[c9zx]

+1 on Mid-Life's post on the choke, assuming it a Ford choke and not a Holley or other aftermarket choke. Reference Stanglover's post, I'm not a fan of any of the Pertronix equipment. Chuck

 

[Stanglover]

+1 on Mid-Life's post on the choke, assuming it a Ford choke and not a Holley or other aftermarket choke. Reference Stanglover's post, I'm not a fan of any of the Pertronix equipment. Chuck

Doing it again I think I'd look very seriously at a DuraSpark distributor curved for my engine. At least it looks stock.

 

[kcmash]

I am NOT a fan of the PIII either. After a year of trying to get my car to keep running, I returned it and went points. I can now drive my car any time without chasing that f'n gremlin! And, my tach works!

kcmash -not bitter at all