Pertronix install vs. wiring diagram

-
D

dodgedartgt

Well-Known Member
Joined
Dec 2, 2006
Messages
215
Reaction score
19
Hello electrical gurus,

I'm installing a Pertronix Ignitor (original, not II or III). I've confirmed the coil has adequate resistance, greater than 1.5 ohm across the poles when not connected.

Because the '67 'cuda has a ballast resistor (2 terminal), the instructions say to connect the black wire to the negative (-) side of the coil (easily done) and "connect the Ignitor red wire to the ignition switch side of the resistance."

So, I pulled up the wiring diagram for a '67 'cuda from this link, http://www.mymopar.com/index.php?pid=27 Specifically here;
Drawing A - http://www.mymopar.com/downloads/1967/67BarracudaA.jpg and
Drawing B - http://www.mymopar.com/downloads/1967/67BarracudaB.jpg

Now, Drawing B shows a large Dark Blue coming off one terminal of the resistor and going to the positive (+) side of the coil and the paired large Brown going to the ignition switch. From the other terminal, it shows small Dark Blue going to the Ignition side of the voltage regulator and the paired small Dark Blue w/ Trace going to the ignition switch.

Okay, now the problem, I'm stumped... Since leads from both sides of the ballast resistor go through the bulkhead to the ignition switch, which side side should I be connecting to, and where is the best place, underhood, to tie in, and not butcher anything? I think I have an idea which side, but I don't want to screw it up, void the warranty and waste my $90 some odd dollars.

Whatcha got for me?

Thnx, Mike in FL
 
Hi. If I remember correctly when I installed mine in 2007 I turned the key to on position and only one side of the ballast has power, that is the side you have to connect to. Hopefully someone else will confirm this, 2007 was a long time ago. Bobby
 
QWKSLVR said:
Hi. If I remember correctly when I installed mine in 2007 I turned the key to on position and only one side of the ballast has power, that is the side you have to connect to. Hopefully someone else will confirm this, 2007 was a long time ago. Bobby
Click to expand...

Confirmed. :D

Pull the wires loose from the ballast and the teminal that has power with the ignition on, thats the one.

If you have a four terminal ballast there will be two wires with power to them (One wire only in the start position and one only in the run position.)
Connect the two that have power together and use that as your 12v source.
This makes it so you have a full 12v to the module and coil in both start and run positions.
 
Okay, did that test. With both terminals pulled off, I have power on the Dark Blue / Dark Blue w/ Trace side. So, now I gotta figure a way to connect without splicing into one of them, without ruining the connector. Guess I'll stop at Radio Shack in the AM and see they have a combo male / female spade connector. Then I should be golden.

Mike in FL
 
dodgedartgt said:
Okay, did that test. With both terminals pulled off, I have power on the Dark Blue / Dark Blue w/ Trace side. So, now I gotta figure a way to connect without splicing into one of them, without ruining the connector. Guess I'll stop at Radio Shack in the AM and see they have a combo male / female spade connector. Then I should be golden.

Mike in FL
Click to expand...

That is one of the ways of doing it without altering the spade plug.
 
dodgedartgt said:
Okay, did that test. With both terminals pulled off, I have power on the Dark Blue / Dark Blue w/ Trace side. So, now I gotta figure a way to connect without splicing into one of them, without ruining the connector. Guess I'll stop at Radio Shack in the AM and see they have a combo male / female spade connector. Then I should be golden.

Mike in FL
Click to expand...

I think you are confused.

You MUST connect the resistor connectors together, then hook the original coil wire to the coil, and the Pertronix to the coil +

Otherwise, you won't get "start" voltage, known on the diagram as "IGN2"

Look at the ignition switch diagram

IGN 1 dark blue is "run" and goes to the "switch" side of the ballast, and also branches off and feeds the VR

IGN 2 comes off the switch, brown, goes through the bulkhead and to the coil + side of the ballast. This is start voltage, and must be connected.
 
j061093409 said:
I called petronix tech and they said to bypass the ballast resistor as it is not needed
Click to expand...
Exactly what 67Dart273's post says.
To re-iterate, remove the ballast and connect the two wires to it together (dk blu & brn). Also connect the Ignitor's red wire to those. If the red wire is bare, just add 2 male spade terminals to do so. Use the type w/ full insulation, or wrap everything w/ silicone tape.

As mentioned, if you used just the brn wire, it would spark while cranking and die as you release "crank". If you used just the dk blu wire, it would not spark in "crank", but would as you return to "run" position. It might start 50% of the time in the later case, but 100% is better.
 
Okay, I didn't have any time the last two days. I read through all the post here, and got out there with my VOM to do some follow up. I see what was said about running voltage vs starting voltage at the ballast resistor. But I kept coming back to the Pertronix instructions which said not to remove the ballast resistor.

I called the Tech line and spoke with a fellow (boy, what a dry personality, almost like I was bothering him). I figured if it burnt it up, then it would be on them, not on me...
He said to keep the ballast and power the Pertronix from the ignition run side of the resistor.

I put two wires into a female spade connector to connect to the resistor, On one wire I put a male spade connector to connect to the Dark Blue / Dark Blue w/ Trace side of the harness. The other wire has an eyelet connector with small machine screw connected to the Pertronix hot lead. All covered with heat shrink tubing.

It all works fine and starts the first time, every time.

What I did discover was that the timing was off by (I'm guessing) at least 20'. I had thought that it would be a direct plug-n-play, but I guess the "center line" of the Pertronix module is about that far off from the points "center line".

Thnx for the comments and help,
Mike in FL
 
Thnx 67Dart273

Nope, its no problem. I just broke out the timing light and retarded the timing back into spec. I had installed the Pertronix without even loosening the distributor, figuring that I knew it was already dead on 12'BTDC. Suprise, suprise... LOL

I guess it is just a matter of where the Hall Effect sensor sets inside the distributor body on the breaker plate, compared to where the points sit.

Like I said, it is working great.

Thnx again, Mike in FL
 
Well what you just describe IS the definition of "rotor phasing."

If phasing is correct otherwise, changing the mechanical advance as it rotates cannot change phasing, because the rotor and the points cam move together.

But vacuum advance and the position of the points (Pertronix) is a different matter.

You MAY have an issue

If you do not want to check this, file this away in the back of your mind. In a few months, look in the cap and rotor, and see if you can detect any "carbon tracking" on either side of the contacts in the cap.
 
dodgedartgt said:
... But I kept coming back to the Pertronix instructions which said not to remove the ballast resistor. ...
Click to expand...
The original Ignitor (you have) does require a ballast. However, that can be within the coil itself (termed "ballasted coil"). Mopar made those, which I think are the ones labelled "for use only with electronic ignition".

Your post #1 says you measured your coil has >1.5 ohm resistance. If true (tricky to measure correctly), then you do not need a ballast, since you have a "ballasted coil". You will get a much weaker spark if you use a ballast plus a ballasted coil.

67Dart273 is correct on "rotor phasing". You have not checked that. To do so, you must punch a big hole in a spare distributor cap and shine the timing light to see where the rotor is rel. to post #1 when the #1 plug fires. Presumably Pertronix designed their unit so it aligns correctly, but doesn't hurt to verify. Even some Mopar pickups had phasing issues (rehrinberg on ebay sells a fix-it kit). The Crane Cams XR700 kit I installed details how to verify correct rotor phasing. That was put in their later manuals, which suggests there were problems in the field.
 
I will follow up on rotor phasing issues. Again, I thought it would be perfect just dropping it in.

Here is how I see it... The Ignitor will fire the coil at a set point on the distributor shaft rotation... the distributor is hard connected to the cam... Rotating the distribuotr (ie, . setting the timing) will vary when that event happens in relation to crank/piston position. I don't see that anything else will change. I don't think it is any different than an aftermarket built distributor being to other specs than a factory distributor. It still rotates 360' for every two turns of the crank... just fires in a different psition... So, I set the timing. So far, in my test drives, I can see no downside to this swap.

Mike in FL
 
Hey Bill G,

I have to check part numbers, but I have every reason ,including a part number on the coil, to believe the 80K-something miles on the odometr is original to the car.

Right now,the car drives at least as good as it did on the 3400+ miles cross country last month, on points, that kept failing and needing replacement.

BTW, after our cross country trip, my just turned 16 yrs daughter now knows how to "field install and set points" on the side of the road. (Definitely easier on a small block than a S/6).

Mike in FL
 
dodgedartgt said:
I will follow up on rotor phasing issues. Again, I thought it would be perfect just dropping it in.

Here is how I see it... The Ignitor will fire the coil at a set point on the distributor shaft rotation... the distributor is hard connected to the cam... Rotating the distribuotr (ie, . setting the timing) will vary when that event happens in relation to crank/piston position. I don't see that anything else will change. I don't think it is any different than an aftermarket built distributor being to other specs than a factory distributor. It still rotates 360' for every two turns of the crank... just fires in a different psition... So, I set the timing. So far, in my test drives, I can see no downside to this swap.

Mike in FL
Click to expand...

No

There are guys who have found what appear to be factory stock Mopar distributors that are / were out of phase. I wish I knew what was causing it

Points gap changes timing. The vacuum can obviously change timing. EITHER of these changes rotor phase, because they change timing but do not change rotor position

Rotor VS mechanical advance, however does NOT change rotor phase. This is because the rotor and the either trigger wheel (reluctor) or the points cam move together. If they are out of phase, it's either a manufacturing problem, or the bottom advance slotted plate came loose (uncrimped) from the rest of the assy, or else the rotor itself is manufactured poorly

You HAVE to have changed phasing, because the install of the pertronix changed timing. This would be equivalent to "moving the points." 20 degrees is a pretty fair amount.
 
Its not for trying, but I just can't seem to wrap my head around this "change of phase".

In reading back trhough the installation instructions, at no point do they suggest removing the distributor.
1. Remove distributor cap and rotor from distributor...
and the last step
21. The engine can now be started. (Which it did, easily.) Let the engine run for a few minutes and then set timing in the conventional manner.

They way I read this, it was a given that the timing was going to be wrong, or at least different, after installation. The approx 20' difference could be no more than the relationship between where the pick-up is located on the breaker plate and where the 8 magnets are located on the reluctor, which is keyed to the distributor shaft cam. Because of that, it seems to me the maximum the timing could be off would be 22.5'. (Half of 360'/8.)

Maybe I'm being too simple, but I'm unable to read more into it than that.

Mike in FL
 
Phase has nothing to do with timing, even though phasing does change timing to some degree, and while mechanical advance affects timing but not phase, VACUUM advance or points gap (or position of sensor) affects both timing and phasing.

Rotor phase put simply is "that point in the distributor rotation at which the spark is triggered" compared to "that point in rotation where the rotor is instantaneously"

When the vacuum can moves the plate in the distributor, this changes the points position, and changed the timing. THIS ALSO changes rotor phasing. But it is "in the design." That is, between the width of the rotor and the cap contacts and the "target" phasing the maker built into the thing, even though the thing moves, the contacts "should" still be inline. On one extreme, or the other, of vacuum advance, the rotor might be "corner to corner" with the approaching corner of the cap contact. On the other extreme, the rotor might be "corner to corner" with t he LEAVING side of the contact.

But "if something" is wrong, IE bent vacuum advance, distributor wear, who knows? The spark might be occurring when the rotor is BETWEEN cap contacts thus causing the spark to jump, and causing misfire to the adjacent cylinder.

Review those links I posted. There's one or two MSD videos on the subject, they are referring to an adjustable rotor which of course we don't have.

The last thing that also changes both phasing and timing in "normal" terms is points gap, or dwell. If you gap points "too wide" this advances timing, and as they wear, naturally towards "closed" the timing retards. If you were to adjust them to extremes, IE barely closing, they are so wide, or barely opening they are so close, you would find that rotor phase also changed "some."

The thing in the end that is bothering me, here is that you say timing changed some 20 degrees. That is a BIG change and I'd want to find out why.

Let me set up a DRAMATIC scenario in your mind. Let's say we have a working distributor. All set up and timed. We "stop" this at some point and do not move it, and we stop it at the instant the spark triggers. The ROTOR will be pointing "somewhere." We do not move it.

Now, we magically move the points someplace "else." We move them 10, 20, 30, 35 degrees away from this point we stopped. Now we position the distributor so that the points are again triggering. WHERE is the rotor pointing? It is no longer pointing to the plug tower it was originally, it is, rather, somewhere in between.
 
I'll answer simpler. "Rotor phase" means where the rotor tip is when the spark fires. Ideally, it will perfectly align with the copper tower on the distributor cap. It changes slightly with "vacuum advance", but not enough to affect where the spark jumps. If the rotor tip was in-between posts when the spark occurred, it could jump to the wrong post and fire the wrong cylinder.
 
Okay 67Dart and Bill.G.

I finally got the concept of rotor phasing. Thnx for the explanations and links.

So, I called Pertronix tech line again this morning and discussed the approx 20' I had to adjust the timing.

I want to be clear, if you read back to my previous threads, you'll see I had a failed distributor in NE on the way to FL. Then the $28 remam unit from O'Reillys was giving me fits itself. The dist shaft cam didn't have lobes, it had "points" that were wearing off the follower shoe on the points arm. I had the timing set at a shop in NE the first time the points went south after replacing the dist, but I probably had the gap / dwell wrong when that was done. Nonetheless, I was able to get home with three more sets and multiple adjustments. Good thing they're cheap... LOL

What the tech guy did tell me was that compared to a properly adjusted set of points, one would expect to see a change in timing of approx 7' after installing Pertronix Ignitor I. He also said rotor phasing stays within stock specs.

Hope this answers everyone's concerns. I've definitely learned a loe.

Thnx, Mike in FL
 
You must log in or register to reply here.
-

Back
Top