Pertronix installation and ballast resistor.

[Lugnutz65]

Am I confused? Do you agree that a ballast resistor or resistor wire is NOT needed to properly install a Pertronix unit in my distributor?

Sorry for the long post.

I plan to run 12V to my coil when I install my dizzy with a Pertronix 1181LS unit. The Pertronix instructions show that the Pertronix unit MUST have a full 12 bolts to the red wire. There are 2 illustrations in the instructions (see photo below). One shows a ballast resistor and the other is without a resistor.

My 1965 C10 has the AAW Classic Update kit. Installed it myself when I had an inline 230 with HEI dizzy. So I had no resistor. I followed AAW directions for an HEI dizzy to the letter and everything was fine.

Now swapping to V8 SBC 283 with a Pertronix points deletion in the dizzy.
An HEI dizzy needs a full 12V. Fine. I did that. No problems.
A dizzy with POINTS uses either a resistor wire to the + side of the coil or a ballast resistor. I’ve read that if you eliminate the resistor wire or ballast resistor in a POINTS system you will burn up the points fairly quickly. Points need the 12V at startup which is supplied by the wire going from the starter to the + side of the coil. Then when the key is in the RUN position, the resistor wire or ballast resistor takes over and drops the voltage to the + side of the coil down to somewhere just above 9.5 volts.

Since the points are no longer inside the dizzy, I can’t burn the points. So no need to drop the voltage down to less than 12.
As I study the diagram #3 with the ballast resistor, I see that the red Pertronix wire is on the 12V side of the ballast resistor. My coil has slightly over 3 ohms of internal resistance and the Pertronix unit I have requires over 1.5 ohms, so I’m fine there.

[AussieinNC]

In a nutshell, if you currently have 12v to the positive side of the coil you are ok....the Pertronix system will run it fine.

If you have 8.5 v going to the positive side it will still work fine.

It is essentially just acting as an electronic set of points.

The real question is what running voltage coil you are installing....the original type that runs fine on 8.5 volts or a true 12 volt coil.

If you run 12 volts direct to the 12 volt style coil you can remove the wire from the starter to the coil.

You should not run 12 volts permanently to the original style coil.

Coil wiring orientation is the most important component of the install.

[Lugnutz65]

I talked to Pertronix tech.
They said I don’t need a ballast resistor.
They said my coil with 3ohm internal resistance is not going to perform properly. The guy said if I run a 1.5 ohm internal resistance coil then it will run properly. I ordered one of their coils through Amazon.
It was only $30. I figured if I bothered to ask, I should take their advice.
Comments?

[AussieinNC]

Good idea to follow the techs advice and replace the original coil....

Let us know how it goes.

[The Rocknrod]

Yep always follow the manufactures instructions or they can use it against you if it fails.
I purchased a small body HEI and had to find the same coil as you. Flawless (so far).