Coil help ?

Bob NH

Bob NH

Well-known member
"Dumbbell" needs a helping hand. Been reading and reading but it never seems to sink in like it should ! ( probably why I was a poor student in school ?) Question is: On 6v positive ground, if you run a wire direct from the solenoid right hand side to the coil, do you connect to the plus or minus side on the coil ? I have just run tests on multiple coils I have both originals and can style and all but one seem to be OK. I have by passed all of the vehicle wiring because I am not able to start the truck. Had "Bubba's" distributor off and it still looks fine and I made no adjustments to it and reinstalled back on. Where to next ?
 
I hate to do this to you, but let's take one more crack at this from the theoretical end of things. The first thing you should know is that the points that we use can handle up to about 4 amps of current before they start to pit and deteriorate rapidly. Since Ohm's Law says that current=voltage divided by resistance, we can determine the resistance of the coil by application of this formula, since we know two of the factors. 12 volts/3 ohms = 4 Amps. In the same vein, 6 volts/1.5 ohms = 4 amps. Thus, in any ignition circuit, you want 4 amps total current through the coil system. 6 volt systems were designed with 1.5 ohm coils from the start. With a twelve volt system, some genius knew that you would get a hotter spark by running a full 8 amps through the system. This is done by using a 1.5 ohm coil in a 12 volt system, using a ballast resistor to add another 1.5 ohms to the circuit during normal running. Bypassing this resistor makes more power for the ignition system while starting. This is usually done by bypassing the ballast resistor from the starter solenoid. Thus, a six volt system will always have a 1.5 ohm coil, while a 12 volt system could have either a 1.5 or 3 ohm coil, depending on whether it has a ballast resistor or not. A multi-meter is invaluable of determining the internal resistance of a coil.

Pre '48 Fords are different, in that they have a variable resistor, not a ballast resistor. This type of resistor will have zero resistance when cold, allowing a full 6 volts to go to the coil on initial startup, but will then heat up when used. which will increase crease the resistance, therefore reducing the voltage to the coil (and therefore the current in amps) across the points.

I have to say that I have little knowledge of the "ever popular" Skip's Coils so have no knowledge of how they work within the system.
 
Last edited:
Explain Right hand side of solenoid? The big fat terminal or the little one?
If you are just trying to "hot wire" it, remove the wire on the coil that does NOT go to the distributor and run a jumper wire, to that terminal, from any permanently live (-) terminal.
 
I am looking at the firewall from front of vehicle and solenoid, starter is on large left terminal, small center stud and right side has large terminal I am tapped into. From this point, which do I connect to on coil ? + or - ? That was my question.
 
If your car is still positive ground, you would connect the "hot" wire from the solenoid to the negative ("-") on the coil. The other wire from the coil (which may be entirely inside the distributor) goes to the points, which when they close go to ground ("+").
 
Good morning guys, I just wanted to give a follow up to my misery. A neighbor came to the house last evening,(he is tinkering with a 46 CJ2A) and we went systematically through all of the ignition system wire by wire ,rotor, dist, etc. Finally, he says, "have you taken out the plugs and checked them"? Took first one out right bank and it was a bit sooty. Took them all out and cleaned them, put them back in and STARTED the truck up ! I never in my wildest dreams would have imagined dirty plugs would cause such a freakin night mare ? I am truly embarrassed for such a simple over sight. So pleased you folks were patient with your suggestions, Thanks again,Bob
 
Back when I was young and foolish, I was into snowmobiling. Every once in a while an engine would refuse to start. The first thing we did was pull the plugs and check them. More often than one would think, the plugs would look perfect, but a new set of plugs and the sled would start on the first pull. Whether this can be ascribed to the vagaries of two-cycle engines or not, it does show what can happen when plugs are compromised.
 
Back when I was also young and foolish also, I had two different "Rupp" snow machines and always seem to have trouble with plugs. In all my years messing with old Ford's, I never remember having this kind of issue. Even at 88 u still might learn a thing or more !
 
You must log in or register to reply here.
Back
Top