Doc here, imp:

Nightfire,

The - on the coil has nothing to do with the ground of the coil,(Coil Body) It is the points lead To the Dizzy. (which is an intermittent ground , On/Off as the points open and close , Buffered by a Cap.)

This follows suit on ANY car, positive or Negative Ground..

If you ground that wire it will not run..AND you'll burn the coil out..

The + side goes to the Ballast resistor and to the Ignition Wire to the switch..

So no, it is correct, since a coil does not care which way a ground or power comes from, It will not effect it's operation (possably Magnetically, but I think your OK..If it fires and runs well, and remember, when the points close, they are actually on + for a ground, so it's all going in the right direction)..

A polarity Sensitive device would, (a radio, or Tach, or any semi conductor device, a DC motor) but like a headlamp..a coil of wire is a coil of wire..ground and power..

To be 100% Technically Correct , the coil would have needed to be mounted Isolated off body ground, The ballast resistor and Ignition Wire would attach to the coil body, and the + side of the coil would be grounded to the body, and the - side to the points..But that is not necessary.

Doc

 

Nightfire, is the truck still a 6 VOLT system, or has it been converted to 12 volts?? 6 volt systems are positive ground.

If it is still a 6 volt system, then the power wire for the coil would go to the negative side of the coil, and the distributor wire to the positive terminal of the coil.

12 volt systems are generally negative ground, with the coil being wired opposite of the 6 volt systems, power feed to the positive, distributor wire to the negative post on the coil.

 

Doc here, imp:

If you reverse the + side of the coil and the - side of the coil, you have effectively changed the coil from a step up transformer, to a step down transformer..regardless of the polarity of the Vehicle..

In a standard coil, the turns ratio of the primary to secondary is about 1 to 100, for every 1 turn on the primary side (+) to 100 turns on the secondary side..(-)

Those turns are mounted on a common Core, and the cutting lines of force through the inductor from primary to secondary is what builds the induced voltage..

Each set of windings are grounded through the Coil body..

To reverse the coil polarity to match the vehicle, you would have to isolate the coil body OFF the car body by means of an insulator, and hook the coil body to the Ignition switch and ballast resistor..

The + side of the coil would then attach to a body part, or positive on the frame..

The - side of the coil would still go to the dizzy..

I don't think any change is need from what you have now So long as it is + to ballast/Ignition and - to the dizzy....the only thing to be gained is changing the magnetic direction of flow from clockwise to counterclockwise..and for an Ignition Coil, It does not care which side it gets power/ground from. The primary side is not polarity sensitive.

Doc imp:

 

Past all the smoke screens and other stuff, 6 or 12 volts?

6 volts, positive ground, power feed to neg side of coil, dist to pos.

 

DOC your posts make my head hurt.. I think I got it though

I found the easy way to tell wether its pos or neg ground is the posts are different sizes My Zephyr was originally pos ground but at some point converted to neg ground. I just hooked it up the way it fit and it fired and ran fine.

 

Nightfire, is the truck still a 6 VOLT system, or has it been converted to 12 volts?? 6 volt systems are positive ground.

If it is still a 6 volt system, then the power wire for the coil would go to the negative side of the coil, and the distributor wire to the positive terminal of the coil.

12 volt systems are generally negative ground, with the coil being wired opposite of the 6 volt systems, power feed to the positive, distributor wire to the negative post on the coil.

not all 6v systems are pos ground, GM used neg ground on there 6v systems, my '51 Chevy is - ground. His Dodge is + ground 6v. Ford and dodge are 2 that come to mind, using 6v + ground

 

After reading through all of this I must say that Doc has given correct information as well as Matt167.

 

Past all the smoke screens and other stuff, 6 or 12 volts?

6 volts, positive ground, power feed to neg side of coil, dist to pos.

Doc here, imp:

NO Sir, ..

The Coil polarity WILL not change because of a Voltage polarity change...

THE VOLTAGE at a Coil or transformer is INDUCED..other than a common ground..the coils have nothing to do with each other physically...only electronically...

IF you reverse the Coil + and - at the top of the coil , you HAVE effectively turned it into a STEP DOWN transformer..NOT changed the Polarity of the coil..

You will note on the PRIMARY side..the side with FEWER turns of wire, Lower voltage , Higher Current draw..it has power and ground..(the + side of the coil) The ground between the PRIMARY and the SECONDARY are common to the coil body (or coil can) ..

The Secondary side of the coil (The one that has many more turns than the primary) Is the High Tension side..Lower Current draw, Way higher Voltage.

The difference between the primary and the secondary windings as you look at the illustration, is the TURNS RATIO..In a Standard Ignition Coil..It has a ratio of (primary side) = 1 To (secondary side) = 100..For EVERY single turn on the + side of the coil, there are 100 turns on the - side of the coil.

On the Secondary side of the coil, The - side of the Windings are tapped before ground to go to the driven Device..(not shown in illustration) In other words to the points or Pickup and module..

As they open and close (spark to ground) they make the Cutting lines of magnetic force "Bounce " across the inductor Core..(The thing the windings are on..) This produces the INDUCED High Voltage SPIKE at the secondary side to the points and the tap to the Rotor pickup.

Try it yourself..With an ohm meter measure the primary side of the coil set for an R X 1 Scale..It will read less than an OHM..Then set your meter for R X 10,000 or higher ohms..and measure the secondary side .. It will read between 10,000 and 11,000 Ohms..no Magic there, just more wire wound in a coil around an Iron core.

NOW if you reverse the - side of the coil,(more windings) and the + side of the coil (less windings), you have 100 windings on the primary side (the key switched side) and 1 winding on the secondary side..(what should be 50 KV side)

If you could get a pulsed 50 thousand volts on your Ignition switch lead to the coil (the wire coming from the switch)..you could produce a nice 12 volts at the + side of the coil ..In other words an INDUCED 12 volts on the + side which now goes to the dizzy.., If you COULD get a spark at all, it would be anemic and not a very good source of ignition.

To actually reverse the coil polarity (where the coil body is now Ground according to the battery, and the + side 12 volts according to the battery) is By putting the ignition wire from the switch and ballast resistor To the coil body side, which would need to be on an ISOLATED mount from the car body, and the + side to the body of the car, (positive, in a positive ground vehicle) BUT This only changes in polarity is the direction of cutting lines of magnetic force..(look at the little arrows on the core in the Illustration) instead of going clockwise, they will go counterclockwise..

On an Ignition coil I think it will have little consequence..except possibly making the spark jump from the ground electrode to the center conductor on the plug (fire backwards..)

No smoke screens..(unless you forget that metal parts are ground on a coil , not the - terminal..and power is the frame on a positive grounded car.. ain: )just Basic Electronics..

Doc imp:

 

DOC your posts make my head hurt.. I think I got it though

I found the easy way to tell wether its pos or neg ground is the posts are different sizes My Zephyr was originally pos ground but at some point converted to neg ground. I just hooked it up the way it fit and it fired and ran fine.

Doc here, imp:

Take two aspirin and call me in the morning...

Yes, you are correct..Your BATTERY usually has different sized posts, If not color coded..to avoid Confusion.

But what He was saying (Nightfire) was about the + (ignition power) and - (point and high tension power) at the TOP of the ignition COIL..Primary and secondary..If he did that it would step DOWN the windings on the coil core..not change polarity..Only making it run like crap in a can if at all..

Doc imp:

 

After reading through all of this I must say that Doc has given correct information as well as Matt167.

Doc here, imp:

Thanks Henry.. :thumbup:

It's easier to explain face to face than it is in text.. ain:

And Matt, yes , there are both positive and Negative 6 volt systems out there..I read once (I and I don't know if true..) They tried it to eliminate Electrolysis on the electrical system .. It might be..I never scraped Barnacles off a Positive Ground System before...

Doc imp:

 

Doc here, imp:

Thanks Henry.. :thumbup:

It's easier to explain face to face than it is in text.. ain:

And Matt, yes , there are both positive and Negative 6 volt systems out there..I read once (I and I don't know if true..) They tried it to eliminate Electrolysis on the electrical system .. It might be..I never scraped Barnacles off a Positive Ground System before...

Doc imp:

That's an interesting concept, what is electrolosis in the electricle system? I know electrolosis in the cooling system means there is a small amount of electricty in the coolant, measured with a DVOM in millivolts.

 

That's an interesting concept, what is electrolosis in the electricle system? I know electrolosis in the cooling system means there is a small amount of electricty in the coolant, measured with a DVOM in millivolts.

Doc here, imp:

It's that white powered crap you find all over the alternator(modern vehicles) and in the old wires.., and it will also eat a Water pump impeller up like nothing (Alternator mounted over the WP)

Dissimilar metals are usually the Cause..where water and electrical move..

Doc imp:

 

IIRC from my ignition class (30 years ago), the primary is not grounded through the case. It is grounded through the points. When the points close, the magnetic field builds up in the primary. Due to the resistance in the coil, the build up is relatively slow and not conducive to a voltage being built up fast enough in the secondary. However, when the points open, the field collapses rapidly, inducing a high voltage in the secondary. Reversing + and - leads on the coil does not change it from a step up to a step down. The only thing it does is change the polarity of the secondary voltage spike, causing the spark to jump (IIRC) from the ground electrode to the center electrode. Final IIRC, the plug fires the mixture better if the polarity fires the spark from the center to the ground. So while I think you can get it to run hooked up backward, it will run better hooked up correctly.

 

Doc here, imp:

OOPS! My bad ain: ..Give Red A Cigar.. :thumbup:

I actually had to look a Cutaway of a coil to see what I was missing..I was referring to a Transformer (which bas icily a Coil of sorts..) and applying it to a coil nomnclature..in total error.

What I should have said was what he said, the primary is controlled by the points through ground and the Secondary is the high tension output at the center tower..(coil wire) NOT the - side.. So if you reverse it at the + and - side it won't step up or down (where on a Transformer it would) The rest is essentially correct..

Dang .. I hate it when I make a bad.. :nono: Sorry for the confusion..And Good Catch Red.. :thumbup:

Doc imp:

 

I was about to chip on this one but redsdad sorted it out. Incidentally, the coil doesn't ground through the casing thus solid epoxy coils like Accels work just fine attached to plastic like mine is.
And yes, through experience I have found that most vehicles will run and function reasonably well with the coil wires reversed. Just not as well as they should. This can cause considerable hair pulling and blaming of carburetors until the reversal of the wires is finally noticed.
And incidentally, old Harleys with points ignitions use "collapsing field" coils while newer ones with electronic ignitions use "rising field" coils. Both look identical if they aren't marked. Either can be hooked up with the wires switched and work just fine as they have no "positive" and "negative" like car coils. But....if you put a late model coil on an early Harley the coil will overheat about 300 miles from home. You will then be forced to take an interest in rising fields versus collapsing fields if you want to get back home. Like I did.

 

dang it redsdad.....Doc has fixed atleast 20 of my "whoops"....score is 20 to "0".....wanted 1 point on my side...

(doc, side note, figured out the 850W coil ad error, 40kv x .02a out=800W...wrong decimal place)

 

Doc here, imp:

Thanks Red65..

And :thumbup: on the Decimal point..

Gotta slow down here, got too many mixed projects going on at one time, keeping up with then all is catching up with me..

Doc imp:

 

coil

IIRC from my ignition class (30 years ago), the primary is not grounded through the case. It is grounded through the points. When the points close, the magnetic field builds up in the primary. Due to the resistance in the coil, the build up is relatively slow and not conducive to a voltage being built up fast enough in the secondary. However, when the points open, the field collapses rapidly, inducing a high voltage in the secondary. Reversing + and - leads on the coil does not change it from a step up to a step down. The only thing it does is change the polarity of the secondary voltage spike, causing the spark to jump (IIRC) from the ground electrode to the center electrode. Final IIRC, the plug fires the mixture better if the polarity fires the spark from the center to the ground. So while I think you can get it to run hooked up backward, it will run better hooked up correctly.

THIS GENTLEMAN IS 100% CORECT just look at a 1956 motors repair manual, which i did andthey tell the same story. cliff

 

positive ground coil

This is easy stuff for a british car guy. If the the car is positive ground the ignition coil should be hooked up reverse of negative ground cars. The positive pole goes to the distributor and the negative goes to the ignition wire from the switch. The coil will work both ways ...but it will work better wired properly. forget all the other techno crap and diagrams, just hook it up backwards from negative ground and you will be ok. If you are using a ballast resistor, it goes on the negative side away from the distributor.

 

Im a goof when it comes to electrical, and while I can understand very little of what you're saying Im assuming I should switch my wire going from the + on the coil to the distributor?



Mike

 

Im a goof when it comes to electrical, and while I can understand very little of what you're saying Im assuming I should switch my wire going from the + on the coil to the distributor?



Mike

Doc here, imp:

Happy Birthday Young Man! :thumbup: Another year older! :sweat:

Yes, turns out I was totally wrong, applying the wrong math to the wrong Item... ain: I just hate it when I do that.. :spank:

The Guy's were right..Reverse the coil , and see how it runs..Go with whatever runs the best. + to the Distributer, - to the ballast resistor and Ignition.

Doc imp: