Jumped ballast resistor...

[brigond]

I was exploring my recent purchase . A 1971 charger SE. I noticed that the ballast resistor had a wire jumping the two connectors. I looked under the distributor cap and noticed there are no points. So I'm thinking the reason for bypassing the ballast resistor is the electronic distributor. Am I correct or is the ballast  resistor still needed ?

[tan top]

have a look at what ignition coil you have  , Some    you can run with out a ballast
having just said that , it could just as well be a tempory fix , for a dead ballast resistor or something 

[gsniegow]

Preface:  I am NO expert, I just want to share my experience and thoughts in case it can be beneficial...

Last year I picked up the MSD Blaster II coil.  After reading the instructions I was led to believe that I could bypass the ballast resistor as it stated that it could handle the 12V.  Long story short I ended up buying a total of 3 MSD Blaster II coils last season.  One even melted / exploded all over the engine bay on me!

After further research and input from the knowledgable folks on this board I came to realize that my issue was the fact that I bypassed the ballast resistor!  Best way I can explain it (as it was explained to me) is that the MSD Blaster II coil CAN handle the 12V but NOT a constant 12V.  If I had been using the MSD 6AL box, then I could bypass the ballast resistor becasue that box sends "pulses" rather then a constant current.  My Mopar electrical ignition on the other hand sends a constant 12V which ended up heating and burning up coils relatively quickly.  (At least this is what was explained to me)

Hopefully that made sense.  As mentioned, I'm no expert but logically the explanation made sense to me.  Once I put the ballast resistor back in place I no longer had any issues with the coil.

NOTE:  Before she hits the road this season, I will be replacing the Mopar electric ignition with the MSD 6AL box and I will let everyone know if I have any more issues, though none are expected.   

[brigond]

Thanks for replying . so I may need my ballast resistor  even though I no longer have points?
What are the symptoms of a bad ballast resistor ?  if I remember correctly  th.e car won't start .I'm thinking of reconnecting it . first I'm going to inspect the coil .

[John_Kunkel]

If it has no points it's probably been converted with a Pertronix or similar. With a stock coil the Pertronix needs the ballast but with their coil one isn't needed.

[brigond]

Hmm. I took a better look . I noticed that they  spliced a wire in to one of the ballast resistor wires . This wire is spliced in to the ignition control unit.

So ...... they jumped the ballast resistor and tapped into one of the "jumped " wires . This wire this tapped wire goes to the ignition control unit. There are no points under the distributor cap. This all seems very purposely done. Another thing I noticed is the cylindrical part ( don't know what its called ) that sits on the coil , is not connected. There is only one wire on this cylindrical part.
I'm now hesitant to re connect the ballast resistor.

I'm not having any problems but I would like to know why . and is this a half assed set up or something acceptable having to do with an ignition modification.

[gsniegow]

This is how mine is also setup...

Ballast Resistor (Passenger side)

• Light Blue w/ Tracer - Connects to the orange box
• Dark Blue - Connected to voltage regulator (stock, I bypass)

Ballast Resistor (Drivers side)

• Dark Blue - Connects to positive side of the ignition coil
• Brown - Bulkhead connection Q

Now, I believe that describes the right way when you are using the Mopar Electric Ignition but I can't say with 100% certainty.  

BTW - A friend encouraged me to document any and all changes I make to the car, especially the electrical system.  I would encourage you to do the same.  I have a handy Visio document which I was able to quickly reference where I had documented that change (I installed a 1 wire alternator so no longer needed the voltage regulator).  Just something to consider...

[brigond]

This is how mine is also setup...

Ballast Resistor (Passenger side)

• Light Blue w/ Tracer - Connects to the orange box
• Dark Blue - Connected to voltage regulator (stock, I bypass)

Ballast Resistor (Drivers side)

• Dark Blue - Connects to positive side of the ignition coil
• Brown - Bulkhead connection Q

Now, I believe that describes the right way when you are using the Mopar Electric Ignition but I can't say with 100% certainty. 

BTW - A friend encouraged me to document any and all changes I make to the car, especially the electrical system.  I would encourage you to do the same.  I have a handy Visio document which I was able to quickly reference where I had documented that change (I installed a 1 wire alternator so no longer needed the voltage regulator).  Just something to consider...

Thanks for the detailed description . I'm going to copy this for future use . in case I need to revert back to the original set up .. I do have a manual on its way . I'm just waiting for it 

So what is the symptom of a bad ballast resistor . it won't start ?

[gsniegow]

The Light Blue w/ Tracer is part of the Mopar Electrical Ignition and not the factory standard, so I doubt you will find that in the manual.

If the ballast resisor is bad, I don't believe any power will be sent through the dark blue wire which connects to the ignition coil.  No power at the coil, no start. 

[tan top]

Preface:  I am NO expert, I just want to share my experience and thoughts in case it can be beneficial...

Last year I picked up the MSD Blaster II coil.  After reading the instructions I was led to believe that I could bypass the ballast resistor as it stated that it could handle the 12V.  Long story short I ended up buying a total of 3 MSD Blaster II coils last season.  One even melted / exploded all over the engine bay on me!

After further research and input from the knowledgable folks on this board I came to realize that my issue was the fact that I bypassed the ballast resistor!  Best way I can explain it (as it was explained to me) is that the MSD Blaster II coil CAN handle the 12V but NOT a constant 12V.  If I had been using the MSD 6AL box, then I could bypass the ballast resistor becasue that box sends "pulses" rather then a constant current.  My Mopar electrical ignition on the other hand sends a constant 12V which ended up heating and burning up coils relatively quickly.  (At least this is what was explained to me)

Hopefully that made sense.  As mentioned, I'm no expert but logically the explanation made sense to me.  Once I put the ballast resistor back in place I no longer had any issues with the coil.

NOTE:  Before she hits the road this season, I will be replacing the Mopar electric ignition with the MSD 6AL box and I will let everyone know if I have any more issues, though none are expected.    

i'm no expert either & don't mind admitting i'm a little confused with all the infomation out there,

ive read loads of  stuff on the internet where MSD coils have been dieing prematurely , previously have always run the stock mopar oil filled coil , with either the points distributor  or the electronic ignition & orange box , with approprate ballast resistors ,  5 months ago i fitted a msd epoxy filled coil & their ballast resistor , & has been running perfect no trouble at all , but depending where you read  some say no ballast is needed or such & such ohm resistor is required , its confusing , so even though there has been no problems with mine , curiosity has my brain thinking  
what i have been trying to find the info on ,  how do you work out the ohm to volts , ie how many ohms resistor does it take to reduce the voltage   say 1  volt  or 1.5 volts  2 volts  etc etc & so on !! or is it not how it works  

even though the orange box electronic ignition has been working perfect apart from one magnetic pick up i had to change
going to swap the lot soon for the complete MSD digital 6AL set up too  

[mhinders]

There is one simple, very useful universal law, it's called Ohm's law. It says that U=I*R (U=Voltage, I=Current, R=Resistance).
Once you understand this one you have everything you need for the majority of electrical cases in a car. The alternating current inside the alternator is a little different, but that's the only place.

U=I*R (multiplied by) can be transformed to I=U/R (divided by) and R=U/I.
Power dissipation is calculated as P=U*U/R which is the same as P=I*I*R

Now you have all the tools for doing whatever calculations you need.

Example: A Pertronix FlameThrower III coil having 0.3 Ohms primary winding resistance.
Assuming charging voltage 13.8V
a) current thru the winding will be I=U/R = 13.8/0.3 = 46 Amperes
b) power dissipation will be P=U*U/R = 13.8*13.8/0.3 = 635 Watts (like 10 pcs of H4 halogen bulbs...now you understand why coils go up in smoke).

To get a powerful spark you need a coil with a big current, I= U/R, which means that you either need high voltage, or low resistance, or both.
The big red aluminium boxes use sophisticated electronics to step up the 13.8V to over 400V before it's passed thru the primary winding in the coil. This gives a powerful current pulse thru the coil and big energy levels to the spark.

If you are stuck with the 13.8V you need to have lowest possible resistance in the coil to get a powerful current pulse thru the winding (I=U/R).

With a ballast resistor in the circuit you limit the current, and thus you limit the energy in the spark, which is something most people don't want.

The ultimate budget goal is to have as energy rich sparks as possible without big boxes stepping up the voltage. We have the 13.8 Volts and want as low resistance as possible in the coil, to get as much energy as possible to the spark. Using a ballast resistor is out of the question for the performance minded engine builder.

So what we have now is a high current (= low resistance) coil, and no ballast resistor, i.e. a coil that will burn to ashes if we don't control the current.
For instance, the Pertronix Ignitor III (which I have myself with the 0.3 Ohm coil) writes "Built-in reverse polarity and over current protection shuts down the system, preventing component damage". The "over current protection" means that the current thru the coil is limited to safe values during "engine stalled, ignition on, no ballast", "very low rpm" etc.

Ignition coils that survive "engine stalled, ignition on, no ballast" for a longer time are usually high resistance coils (= low current = low energy = weak spark ), and not the type of coil a performance minded engine builder wants to use.

For performance you need a low resistance coil and an electronics module that control, and can limit, dangerous current levels.
You will not find a high performance coil that will survive "engine stalled, ignition on, no ballast" if the ignition system has no current control.

Sorry for the long text...

[tan top]

     thanks for sharing this info mhinders  
 sort of understad i think maybe , but mostly going over my head , this kind of stuff did when i was in collage too ,  
will study it &  make sure it sinks in & look up other coil specks  
thanks again  

[brigond]

Yup, a bit over my head too. Thanks for the post though. What I'm getting out of this is..... That there needs to be resistance  to control the current  through the coil or it will fry. I don't know if I have that . I'm a try the jump wire  and see what happens .

[mhinders]

Yup, a bit over my head too. Thanks for the post though. What I'm getting out of this is..... That there needs to be resistance  to control the current  through the coil or it will fry. I don't know if I have that . I'm a try the jump wire  and see what happens .

Since I don't know what parts you have in your car...but if it works I would not change anything at least for now. Most likely your electronics module contains a current limiting feature and no ballast resistor is needed.

As far as I understand, if it's a Pertronix module of the 1st version it doesn't have this current limiting feature built in, and will need the ballast resistor. If it's a Pertronix module version II or III no ballast resistor is required.

[brigond]

Yup, a bit over my head too. Thanks for the post though. What I'm getting out of this is..... That there needs to be resistance  to control the current  through the coil or it will fry. I don't know if I have that . I'm a try the jump wire  and see what happens .

Since I don't know what parts you have in your car...but if it works I would not change anything at least for now. Most likely your electronics module contains a current limiting feature and no ballast resistor is needed.

As far as I understand, if it's a Pertronix module of the 1st version it doesn't have this current limiting feature built in, and will need the ballast resistor. If it's a Pertronix module version II or III no ballast resistor is required.

Thank you for your response. I'll just see how it works. If I have any trouble starting it I will look In that direction. I really don't know what it has in it as far as module. I guess there's no way to tell?

[HeavyFuel]

This is how mine is also setup...

Ballast Resistor (Passenger side)

• Light Blue w/ Tracer - Connects to the orange box
• Dark Blue - Connected to voltage regulator (stock, I bypass)

Ballast Resistor (Drivers side)

• Dark Blue - Connects to positive side of the ignition coil
• Brown - Bulkhead connection Q

Now, I believe that describes the right way when you are using the Mopar Electric Ignition but I can't say with 100% certainty.  

BTW - A friend encouraged me to document any and all changes I make to the car, especially the electrical system.  I would encourage you to do the same.  I have a handy Visio document which I was able to quickly reference where I had documented that change (I installed a 1 wire alternator so no longer needed the voltage regulator).  Just something to consider...

I'm no expert either....but I haven't heard of anyone not needing the voltage regulator.     

[71 SE3834V]

This is how mine is also setup...

Ballast Resistor (Passenger side)

• Light Blue w/ Tracer - Connects to the orange box
• Dark Blue - Connected to voltage regulator (stock, I bypass)

Ballast Resistor (Drivers side)

• Dark Blue - Connects to positive side of the ignition coil
• Brown - Bulkhead connection Q

Now, I believe that describes the right way when you are using the Mopar Electric Ignition but I can't say with 100% certainty.  

BTW - A friend encouraged me to document any and all changes I make to the car, especially the electrical system.  I would encourage you to do the same.  I have a handy Visio document which I was able to quickly reference where I had documented that change (I installed a 1 wire alternator so no longer needed the voltage regulator).  Just something to consider...

I'm no expert either....but I haven't heard of anyone not needing the voltage regulator.     

I believe what he is refering to is the 1 wire alternators have a built in regulator so therefore there is no need for the one mounted on the firewall.

[gsniegow]

This is how mine is also setup...

Ballast Resistor (Passenger side)

• Light Blue w/ Tracer - Connects to the orange box
• Dark Blue - Connected to voltage regulator (stock, I bypass)

Ballast Resistor (Drivers side)

• Dark Blue - Connects to positive side of the ignition coil
• Brown - Bulkhead connection Q

Now, I believe that describes the right way when you are using the Mopar Electric Ignition but I can't say with 100% certainty.  

BTW - A friend encouraged me to document any and all changes I make to the car, especially the electrical system.  I would encourage you to do the same.  I have a handy Visio document which I was able to quickly reference where I had documented that change (I installed a 1 wire alternator so no longer needed the voltage regulator).  Just something to consider...

I'm no expert either....but I haven't heard of anyone not needing the voltage regulator.     

I believe what he is refering to is the 1 wire alternators have a built in regulator so therefore there is no need for the one mounted on the firewall.

Correct, sorry if I was unclear...