Two Wire Distributor?

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dustinface

New member
Joined
Nov 15, 2015
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Hey guys! I wanted to first thank all of you for having a resource like this.

I've got a '66 Ford T'Bird w/a 390 4BBL Carb. I just purchased the ol lady about a month ago in quite a few pieces. I've got the parts from the tank to the engine now installed and ready to go, however while I was going through the engine and comparing the information to my Tbird shop manual I noticed something weird.

The distributor has a positive and ground wiring coming out from inside of it. Both of those wires (+ & -) are then hooked to the ignition coil. There then seems to be a wire coming from the firewall to the ( - ) side of the ignition coil. I've looked at the wiring schematics, online and nothing that I see has reference to this type of distributor setup. I then started looking at more of the electrical and noticed a few other interesting things such as the positive side going to what looks like the block. I've attached a few pretty large images of the wiring so you can see a little better.

The reason why I even bring all of this up is that I've been testing the spark. The distributor turns, but the wires are not getting any spark... so I was going to buy a new distributor, starter relay, new wires, etc... but thought I'd get the first question out of the way first.

Is there something missing that I am missing from the ignition coil? Are the wires from the distributor supposed to go to the coil? Has anyone seen a 2 wire distributor, the ones I've researched are all 1 wire.

Any other information would be greatly appreciated.

Thanks!

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Looks like you have a Petronix Ignition setup. Google Petronix trouble shooting they have wiring diagrams and tech support
 
Boaterbob is correct, you have a Pertronix ignition. The last photo shows the Ignitor module in your distributor, but it's old. Per-Lux changed it's name to Pertronix in 1991, so it's performance may be suspect. 25 years wouldn't be a bad life expectancy.
The black Ignitor wire goes to the "-" on the coil and the red goes to the "+". A switched 12 volt source is also attached to the "+" terminal of the coil. This cannot be the original 12 volt coil wire because that had a resistor to drop the voltage once the engine got running. Pertronix needs a full 12 volts all the time.
If it's not working, consider getting a new Pertronix for about $75.
Hope this helps
Terry
64HT
 
Ok. Yes, I did some googling around and did find the company when I opened the Distributor in the first place. I thought it was really weird concerning that the OE only had 1 wire.

I guess now my question is, if I go back to the stock setup (with my pictures above) will I need to change up my wiring everywhere or can I just drop the OE distributor & parts in there and try to start the ol gal again?

BTW, Terry, that is good to know that its old. I was going to contact them and ask them to asses the part, but now that I know that... if wiring will be an issue I can just get a new one or maybe a better replacement (any recommendations?). I thought it was weird because the wires look brand new, but it sat for quite a few years so maybe that was one of the last pieces added to the car before it sat.

Also, based on your information they had it installed incorrectly. When I got the car they had the + wire going to the - side of the coil. I wonder if that did something too. LOL.

Any other information that you could provide me would be excellent and thank you for the info thus far guys! : o)
 
The routing of the wires you describe is weird. It's been a long time since I played with my Pertronix, so I'm not sure if the module has polarity stamped on it. I do know that over the years the wiring colors have changed since I have seen one with white and black, but I can't see them using red for anything other than positive.
Go to the Pertronix site and download the instruction sheet for model 1281. That will give you the wiring setup. It sounds like your setup might have retained the resistor in the circuit, which is more complicated than it has to be. You need a 12 volt source that is switched, eg on only when the key is. The easiest access is to splice into the switched wire at the voltage regulator. On a 64 it's green/red, but yours looks like a 65, so I'm not sure of the color. Easy to check, 12 volts when engine running, nothing when off. That wire goes to the positive side of the coil and the Pertronix module goes red to positive and black to negative.
That should be it. If there was still a resistance in the 12 volt feed to the coil, the Pertronix wouldn't work properly but you would still have had spark.
I think trying to sort wiring out and go back to the old points would be tough given the layout you've described. Modules are available everywhere.
Terry
64HT
 
Yes. That's what I've been working against. Its always tougher to jump into someone elses projects without knowing the scope and with the information you guys have provided I have learned a few things.

I called the manufacturer today and they also said that the Ignitor is probably 20 years old (if not older) too, so you were right about that one. He said that it sounds like I have a Positive Ground system, which is probably why I was firstly thrown off (use to Negative Ground setups). The Positive side of the battery is grounded to the block, while the Negative is hooked to the solenoid. He did mentioned that the wires should be black and then black/w/white on the ignitor, rather than red and black, but that its several versions back from what they have now.

I asked them to email me so I can send them the images I have so that they can help me track down what part I should be having. I havent seen it come through yet, so hopefully they send me something today so I can jump in the garage this weekend. He did mention that if it was not hooked up correctly that it could be fried now. The issue I'm going to have now is re'learning what I know and think backwards as far as the Positive ground system.

Something else I did notice while digging into the electrical is that the Voltage Regulator (front drivers side headlamp engine bay) has a black wire coming out of the wire cluster but is just hanging out with nothing hooked into it. That will be fun to track down too (unless you guy know what that should go to, too? lol).

The last thing I can say is that when I first started getting into these issues, when I turned the key my spark plug tester (the fancy light) did flash. However, when I continued to turn the key it stopped. Im pretty sure I just need to keep asking questions and keep my head under the hood I'll get it figured out.

It hurts to be in the Scottsdale area this week, the Goodguys Car Show is going on, cars everywhere and this is the 2nd year out of 5 that I've lived here and haven't been able to take a car in the show with me.

As always, any information you can provide me is always accepted! Look where it's gotten me this far! Thanks.
 
You do not have a positive ground system. Maybe someone put a dead battery in and tried to charge it backwards dunno. A extra wire comes out of the harness that plugs into the reg., But that should be for the radio condenser and that is yellow on a 66, Dunno color on 64. seems like you must get a Jim Osborn wiring diagram book and shop manual to straighten out your wiring situation before you start buying and switching componets.
 
I agree with Boaterbob, there's no way you have a positive ground system. Things like the heater motor wouldn't work, not to mention the windows (if you have them). I don't even want to think about the starter.....
It would help to know what year this car was so we can identify wire colors.
As he said, you need to sort out what you have before you start installing new components.
Terry
64HT
 
Only one other note. The Pertronics will work with the resistance wire. This does however give you a failure point. Resistance wire is sheathed right off the igniton switch and can fail at the connector where it goes back into regular wire. With the charging system at 14.4 volt on mine I run about 11 volts at the coil with adequate spark.
 
On a better computer now with a better monitor and looked at your pictures better. Your battery IS wired backwards. Your black cable is wired to the solenoid which is on your negative post. I had the pleasure of working on a truck once that had a battery that was charged backwards. Oddly enough the starter worked normally as did a lot of the basic electrical. Just about everything electronic was toast but the radio (91 ford truck). Don't put your pertronics in till you are wired as a negative ground or smoke will roll. Alternator diodes (though his survived) and regulator aren't too happy about it either.
 
Boaterbob, your comment about the resistance wire and Pertronix was interesting. I checked the installation instructions for the Pertronix I bought in 2001 and it warned you that the resistance had to be removed or the unit would probably fail. I see the manual posted by the company now shows both ways.
However, I understand that the reason the voltage to the coil was reduced once the engine was running was to eliminate arcing of the points at higher rpm's. Given that a lot of people go to aftermarket coils to increase the spark voltage, it seems counterproductive to reduce the coil input voltage.
Just a thought
Terry
64HT
 
(That was me Terry). Points arcing was the primary reason for the reduced voltage. The other reason was that original coils were designed to run on the lower current draw so they would not fail to overheat. Even modern electronic ignition ran resistance wire for this reason (Ford Dura spark and Chrysler with the dual resistor block, they run the same oil filled coil with a fairly high current). My bird is a great example of how high the current can get. If I leave the main ignition on without starting it my coil will overheat in about 15 minutes and will not start until I cool it down a bit (and if you touch it it gets pretty hot). Pertronics leaves it grounded in a no run situation. If I ran full voltage to it I suspect I would have burned it up by now. I do have an accel flame thrower coil (fancy name for "gee...its chrome") but it really doesn't run any better or look any different on an ocilliscope than a stock coil. Granted you don't leave the key on that long usually but I do when working on it sometimes. About every oil filled standard coil I have ever bought will say on the coil that they must be used with an external resistor. Makes me wonder what Pertronics is thinking. If you keep the current down across the firing transistor it should run cooler and last longer. Look at all the trouble Ford got into with their TFI modules mounted in the distributor due to heat failure and those were also run with resistance wire. That being said I think Pertronics makes a hell of a product. I have never seen one go bad. I do keep a spare in the trunk as I do a lot of highway driving but doubt if I will ever need it.
 
Headacheguy,
You raise some excellent points worth thinking about. I'm running some version of a "mustard top" coil that I suspect is nothing special. When I get home and put the car on the road, I'll reconnect the dormant wire with the resistance in it and see if there is any noticeable difference. It's gone 14 years with no resistance in the wire to the coil, and I've always been careful not to leave power on if the engine isn't running.
I've now had another thought......I assume in the stock wiring configuration, the "acc" position on the ignition switch does not put power to the coil, but running a separate 12 volt wire from a switched source would. Seems like Pertronix may have outsmarted themselves with the original installation instructions if you use the "acc" position for any time.
Thanks for the info
Terry 64HT
 
You guys are right...

I just got back from the Goodguys Scottsdale show where I was able to track down a guy with a '65. Probably could have gotten there earlier to find a '66, but it justified my concern (and what I'm reading here). It looks like the guy that had this car before me hooked the + and - terminals incorrectly.

The '65 I saw at the GG show had the black wire going to the block while the red wire was going to the solenoid. I know that is what you all have been telling me, what the manual has been telling me, but I trusted that the car was just correctly wired.

I'm going to post some pictures of MY car and show you that the car is hooked up as a positive ground... but the idiot hooked it up incorrectly. Now the question... do I go back to where I got the car from and leave poo on his doorstep?

So, I guess the first step is to rewire the ground to the ground, the positive to the solenoid and then install the new Ignitor (coming tomorrow). Then go through the rest of the wires coming out and to things and ensure those weren't installed improperly.

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I think your saving grace here is that the car is old. If you are lucky it will fire right up and you might have to deal with charging issues (also maybe not). If you ever wonder why the starter works both ways, it changes polarity on the armature but also on the field windings which keeps the rotation direction the same. Might be nervous about the guy who put the battery in. Hope he didn't do any other creative wiring. Flaming poo perhaps...hehe. Post if you have more issues, like I said before, I have actually been through this before.
 

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