I have read what I could on the subject.I installed a pertronix system and flamethrower coil on my 352.It works well but I may need to install a jumper.With the engine running I have 12 v at the positive side of the coil.With the engine off I have 6 v at the ternimal.It would seem that as long as it has 12 v when running it would be ok.Is this correct or do I need to run a wire?
Joe

 

It would seem that you are correct, but there are a couple of questions raised. First, that is not stock to have 12v when running and 6v with "just" the switch on. Makes me wonder whats up with your wiriing (and were you buring up coils and points all the time, previously?). Secondly, the resistor wire can be a little strange -- it may *show* 12v but as the engine reves up, current draw increases and may no longer be able to provide full 12v -- or at least thats how I understood it at some point.

But since you show 6v with *just* the switch on, I'm guessing that the starter circuit has somehow been altered -- stock wiring gives the coil 12v when the switch has energized the starter relay. That is supposed to give a hotter spark to start. Then, when the ignition switch is back to the "on" position, the electricity to the coil is comeing through the ignition switch, and goes through the resistor or resistor wire back to the coil. The 12v that the coil gets when starter is engaged is comeing off the relay itself -- I think!!

I wonder if someone hooked your coil wire from starter relay up to one of the fields from the alternator? Or do you have an alternator? If its been aftermarket rigged or you have the original generator, better check most of what i said against a correct wiring diagram. But I think I am mostly correct.

 

I recently installed a Pertronix on my '66 with 390. After reading the threads here I decided to run a jumper wire. When I disconnected the + lead from the coil and put the ignition switch to ON, it read 12v. However with it hooked up to the coil and ON position it read 6v.

Running a jumper wire is pretty easy mod. Look up under the dash and you will find a short lead comming off the ignition switch connecting via bullet connectors to a thicker pink colored wire. That's the resistor wire. Disconnect it and run some 14guage from there through one of the holes in the firewall to the coil. Disconnect the ignition wire from the coil. Crimp a loop connector at the coil side, wrap the wire along the existing harness, crimp a bullet connector at the ignition switch and plug it in. Done, and you get a solid 12v to the coil.

Cheers,
dagger

 

Dagger did you notice any difference in the performance?Herman,I'm pretty sure the electical has not been molested much.It does have an alternator but Its a 1965 and I think it came with one.Changed the oil and installed a chrome holley air filter set up on it today.I love this truck.
Joe

 

Dagger
Your reply has triggered another question.

I have recently converted my 65, 352 over to electronic ignition. I used a 1976 Ford electronic ignition off of a 360. After getting it running I noticed the very same senerio with the voltage. 6VDC with switch on engine off and about 10VDC with engine on, and it seems to go up to 12VDC when your rev her up a bit.

My question is this. If you remove the resistor wire under the dash
(That I have located) will it harm the system to run the straight 12VDC to the system? I did notice on the system I installed there is two 12VDC suppliesin the Chiltons wire scematic. one is a straight 12VDC while cranking and 12VDC thru a resistor wire while running. Why do they want to do this? And would you recomend it that way?

Thanks

Jon

 

Ford stock Duraspark ignitions do not want full 12v to the coil either. The aftermarket Pertronix Ignitor and Flamethrower (coil) need a full 12v.

As I explained in my post, the full 12v is present during starting to help give the engine a hotter spark. Why not do that all the time? Becuase of some extreemely complicated details left over from the early days of points type ignitions that I cannot explain very well. And I think the coils burned up too.

 

Yup! and Duraspark retards the timing during start mode. A good feature that helps starting. Pertronix= 12V, switch on, engine running or not. Brown wire from starter relay not required. Duraspark less than 12V, switch on, engine running or not. Duraspark gets 12V during start with a 5 degree retard on the timing on the white wire from the starter relay.

 

I have been running duraspark for about a year great improvemnt over points You have to deal with the 6 v on the run side of the coil. A new coil kicks about 40k volts but suffers from heat and I have replaced the coil. Why not turn the system up a notch and replace the 6 v resistor wiring on the run circuit with a new 16 guage geting a full 12 volts and replacing the coil with a tfi solid coil used on the next generation system and it rocks. You kick about 7k more volts on the plugs and eliminates the round coil changing nothing else you have have plenty of reliable spark to run a pretty warmed over engine and get all the spark you need and save your coins on a new name brand coil and module. The TFI coil costs around 20 25 new and needs a new connector to hook up the pos side and neg side. Use a coil wire made to fit that coil. It can be mounted almost anywhere and only needs good connections and go with the good rotors caps and wiring. Brass terminals and fittings over cheaper aluminum contacts. I don't mean that you will go wrong buying a different coil or ignition module to each his own. I believe you will find the new gen ignition system henry hatched beats the highly regarded HEI another brand x uses. My update is ready for me to put her to work. Will advise of trials and groans pro and con.
IMHO
Oldtrapper