Dizzy Confusion

[JMOR]

Measuring such low resistance values with Ohm meter is not real reliable, as making good contact and the leads themselves are in the range of what you are trying to measure. I use a variable DC supply to run a measureable value of current thru coil under test, record voltage across it and calculate resistance. Example: set 4 amps (an easily measured value, not some tiny fraction) , measure 4 volts (again, not some tiny number), and then R= V/I= 4/4=1 Ohm. Something I can have confidence in.

 

[jzimmer238]

Foxtooth, I misspoke. The black wire goes to the ignition not the black/white.

 

[JMOR]

To be really clear, draw schematic, take picture of same & post it.....better than words! Or just follow Pertronix installation instructions & save "words" & "mis-spoken".

https://imgur.com/IutHdhH

 

[olddavid]

I measured the coil resistance by the top post and the pigtail at bottom but must admit I'm not confident. I have two muti meters, one older with the needle, one newer w digital. The older one read zero when I put the contacts together so I used it. The digital one lowest setting is 200, turn it on it reads 1, touch contacts together it dances around but seems to settle on .5 to .7

Be sure to subtract the .5 to .7 ohms from the reading you get across the coil. JMOR has some good advice to get a more reliable measurement.

 

[fOXTOOTH]

I apologize for any confusion and for this rather crude drawing I made, on it is what I'm suggesting I can do. Given that JMOR's drawing on his schematic sez I can install resistor AFTER the coil. All I did was remove the ign wire from resistor block B and connected with EI unit. The connection from top of coil to resistor was already there (OEM set up) but then I made an additional connection from resistor B to ground.

To be really clear, draw schematic, take picture of same & post it.....better than words! Or just follow Pertronix installation instructions & save "words" & "mis-spoken".

https://imgur.com/IutHdhH

 

[JMOR]

I apologize for any confusion and for this rather crude drawing I made, on it is what I'm suggesting I can do. Given that JMOR's drawing on his schematic sez I can install resistor AFTER the coil. All I did was remove the ign wire from resistor block B and connected with EI unit. The connection from top of coil to resistor was already there (OEM set up) but then I made an additional connection from resistor B to ground.


View attachment 103046

Looks good to me and fits Pertronix latest instructions! Good

 

[fOXTOOTH]

Looks good to me and fits Pertronix latest instructions! Good

Thanx, couldnt have gotten this far without the 'gurus'

 

[fOXTOOTH]

I got a more reliable reading on the coil-1.1ohms. Just so I'm clear, if the EI kit calls for only .7 ohms, I should be good to go without any added resistance?

 

[soaked]

Hi fOXTOOTH,
The folded paper instructions that came in the box are what Pertronix wants you to follow. Not the pdf from 7/15. Pertronix changed the chip design in the module. Note the date 12/8/20 ( its almost in the center of JMOR's info)
Ignitors before that date didnt need suppression wires, and had the minumum required primary curcuit value of 0.7 ohms.
Your MINUMUM primary resistance must be 1.5, and must use suppression wires.You will cook the ignitor if only 0.7.

 

[fOXTOOTH]

Hi fOXTOOTH,
The folded paper instructions that came in the box are what Pertronix wants you to follow. Not the pdf from 7/15. Pertronix changed the chip design in the module. Note the date 12/8/20 ( its almost in the center of JMOR's info)
Ignitors before that date didnt need suppression wires, and had the minumum required primary curcuit value of 0.7 ohms.
Your MINUMUM primary resistance must be 1.5, and must use suppression wires.You will cook the ignitor if only 0.7.

Soaked, Maaan now I'm really confused because what came in the box must be the old instructions. They dont look like what JMOR posted and bottom of first page is marked 07/15. They dont go into detail like instructions above do about the balast resistor or the coil, and I thought I was pretty smart by coming up with that on my own (leaving the OEM resistor to coil wire intact and jumping wire to ground from resistor B.) So maybe what I have is the old Pertronix unit? How can I tell??? & if it is, am I add too much resistance with the suppression wires I bought? I attached pix of unit and 'old' instructions that came with it. Can you tell if this is the old unit or the new one?

 

[soaked]

Yes, you have the old one.
Your drawing met JMOR approval, so its correct.

 

[zuhnc]

@fOXTOOTH - Use suppression wires anyway. If you (in the future) need to replace the module, the wires are already there. I have been using Pertronix on my 8N and three generators for over 10 years, and had just one failure (recently). Old age, I suspect, as nothing unusual happened to cause failure. All the units are equipped with suppression wires, and NO, the 40.000KV ignition coil is NOT needed; stock will work perfectly well. Suppression wires work to prevent transient inductive "signals" from interfering with the module operation.

There might be a date code on the module, and a message to Pertronix might inform you as to when it was manufactured.

 

[fOXTOOTH]

Thanx all for the help! I know i ask alotta questions, only because I'm not sure and this is someone else's tractor. I called Pertronix again and that dude said the kit requires the coil has 1.5 ohms resistance, but he didnt know why the old ones only required .7 ohms.... I'm still left with deciding to go with new kit instructions on an older ignitor or older requirements. I'm gonna get after it soon and see what happens
Anybody know what ohms rating are in those aftermarket 6V coils for front mount distributors? I ask the seller (YT) and they dont know, I guess you have to buy one to find out....

 

[olddavid]

Thanx all for the help! I know i ask alotta questions, only because I'm not sure and this is someone else's tractor. I called Pertronix again and that dude said the kit requires the coil has 1.5 ohms resistance, but he didnt know why the old ones only required .7 ohms.... I'm still left with deciding to go with new kit instructions on an older ignitor or older requirements. I'm gonna get after it soon and see what happens
Anybody know what ohms rating are in those aftermarket 6V coils for front mount distributors? I ask the seller (YT) and they dont know, I guess you have to buy one to find out....

I'd say err on the hi side if anything.

 

[deanostoybox]

Thanx all for the help! I know i ask alotta questions, only because I'm not sure and this is someone else's tractor. I called Pertronix again and that dude said the kit requires the coil has 1.5 ohms resistance, but he didnt know why the old ones only required .7 ohms.... I'm still left with deciding to go with new kit instructions on an older ignitor or older requirements. I'm gonna get after it soon and see what happens
Anybody know what ohms rating are in those aftermarket 6V coils for front mount distributors? I ask the seller (YT) and they dont know, I guess you have to buy one to find out....

Front mount 6V will be 1.0 and front mount 12V will be 2.5. May vary plus or minus 20% and be in tolerance. All I have measured have been within 1/10 Ohm plus or minus. With the OEM type ballast resistor wired in as in the wireing diagram JMOR posted, and the one you drew, you will be golden.
You got this

 

[fOXTOOTH]

OldDavid I hear ya & was thinking the same thing, but thought it would be nice to start out with what the manufacturer sez.
Deanostoybox, I appreciate the confidence! the kit DOES recommend using a 12V coil, but again I find the instructions (JMOR above^) vague. They give instructions for 6V application using a 6V coil, and for a 12V application using a 6Vcoil, but not specifically how to wire their ignitor with a 6V pos ground system using a 12V coil, assuming you can use a 12V coil this way, and if it's possible- then what resistance is required? Am I making too much of this? Hoping someone sez- no mr. Foxtooth, your concerns are warranted, the instructions are VAGUE!

 

[Fritz Maurer]

I apologize for any confusion and for this rather crude drawing I made, on it is what I'm suggesting I can do. Given that JMOR's drawing on his schematic sez I can install resistor AFTER the coil. All I did was remove the ign wire from resistor block B and connected with EI unit. The connection from top of coil to resistor was already there (OEM set up) but then I made an additional connection from resistor B to ground.


View attachment 103046

You arranged it with a minimum of wire crossings. Very nice. You should go work for Helm, Inc.

 

[fOXTOOTH]

You arranged it with a minimum of wire crossings. Very nice. You should go work for Helm, Inc.

Do you mean Levon??? lol

 

[deanostoybox]

The instructions for the Pertronix part number 1247P6 which is for 6V positive ground posted by JMOR seems to me to be as explicit as it gets.
It says:
The minimum primary resistance for the igniter is 1.5 Ohms. This is the resistance of the coil and ballast resistor combined.
It says to use suppression core spark plug wires.
When it comes to wiring it has a diagram showing the black/white wire to the concave screw where the "pigtail" of the coil sits. The black wire to ignition switch (-6V) and the top terminal of the coil to the OEM ballast resistor, the other end of the OEM ballast resistor to +ground.

It does not say anything about using a 12V coil on a 6V system. It says if using a 6V coil on a 12V system additional resistance is required and it is better to just use a 12V coil in that case.

I do not see anything VAGUE about it.

 

[fOXTOOTH]

The instructions for the Pertronix part number 1247P6 which is for 6V positive ground posted by JMOR seems to me to be as explicit as it gets.
It says:
The minimum primary resistance for the igniter is 1.5 Ohms. This is the resistance of the coil and ballast resistor combined.
It says to use suppression core spark plug wires.
When it comes to wiring it has a diagram showing the black/white wire to the concave screw where the "pigtail" of the coil sits. The black wire to ignition switch (-6V) and the top terminal of the coil to the OEM ballast resistor, the other end of the OEM ballast resistor to +ground.

It does not say anything about using a 12V coil on a 6V system. It says if using a 6V coil on a 12V system additional resistance is required and it is better to just use a 12V coil in that case.

I do not see anything VAGUE about it.

DTB, what is vague is I have a 6V system, which begs the question- can I use a 12V coil? and if so what resistance is needed?
Also, and not for nothing but when talking with the Pertronix tech, he did say the primary resistance that is required is in the coil, not the "wire resistance" that you get from the ballast resistor...but that's another can of worms I'm not sure I wanna open.