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-   -   Coil Tester needed (https://www.fordbarn.com/forum/showthread.php?t=276467)

v8nut 02-07-2020 05:27 PM

Coil Tester needed
 

1 Attachment(s)
Does anybody have a US source for a coil tester like the one shown. This one is a little pricy on ebay at $50 and I would pay that except it is in Columbia and would be 3 or 4 weeks to get to me. I would like one much sooner than that. Any help would be appreciated. Jim in San Jose.

redmodelt 02-07-2020 07:55 PM

Re: Coil Tester needed
 

https://www.autoblog.com/2016/08/01/...ignition-coil/
https://www.liveabout.com/bench-test...n-coil-4177225
There are a lot more, just google test car coil

VinceBlack 02-07-2020 07:57 PM

Re: Coil Tester needed
 

I made one using an old distributor and spark plug.

v8nut 02-07-2020 08:35 PM

Re: Coil Tester needed
 

What I am looking for is a device that makes and breaks the primary circuit continuously so I can see the spark. I have a tester that measures the primary and secondary winding continuity and resistance. The picture posted is not very clear but there is a blithering continuous blue spark shown. That is what I want to do and see. Thanks for your help, Jim in San Jose.

Bob C 02-07-2020 08:59 PM

Re: Coil Tester needed
 

1 Attachment(s)
I got one like this on Epay.

holdover 02-08-2020 11:15 AM

Re: Coil Tester needed
 

Been using one of these for years, it will show the intensity of the spark, and by using the adjustment wheel how long it is. At $8.00 makes a great gift for gear head friends


https://www.ebay.com/itm/1-Spark-Plu...cAAOSwYDZd-Y5x

katy 02-08-2020 11:53 AM

Re: Coil Tester needed
 

https://model-a-ford.org/resources/t...n/coil-tester/

rotorwrench 02-08-2020 07:33 PM

Re: Coil Tester needed
 

The old Sun CCT-10 coil tester was a very good unit but is still expensive to this day.
It does a condencer test and a coil test.
https://www.garagejournal.com/forum/...ad.php?t=32791

The ones made back in the 50s would even preheat the coils for a good test but they didn't test the condenser and they had no oscilloscope.

fordified 02-09-2020 09:23 AM

Re: Coil Tester needed
 

Quote:

Originally Posted by Bob C (Post 1849789)
I got one like this on Epay.

Sorry to hijack this thread- I have the older version of this Snap-on tester, (the MT-640), but it was missing the adjustment screw/knob when I bought it. I did make a replacement screw/knob for mine but I do not know what the "gap" between the brass points is when the indicator edge of the knob reaches the "green- good" margin is. Bob, if you get a chance, would you please measure this "gap" for me? This gap measurement may help others also with that product listed above on ebay.


Thank you in advance,
Kyle
Holt, MI

Bob C 02-09-2020 01:53 PM

Re: Coil Tester needed
 

From the bottom of the knob to the tip of the point is 1 51/64".
I would like to find the neon bulb. It shows in the picture but the seller
did a lousy packing job and it was broken when it arrived.



Bob

v8nut 02-09-2020 03:06 PM

Re: Coil Tester needed
 

Thanks Katy. That is exactly what info I needed. I will try to build the tester you show. Jim in San Jose

fordified 02-09-2020 06:13 PM

Re: Coil Tester needed
 

Quote:

Originally Posted by Bob C (Post 1850336)
From the bottom of the knob to the tip of the point is 1 51/64".
I would like to find the neon bulb. It shows in the picture but the seller
did a lousy packing job and it was broken when it arrived.



Bob



Bob, thank you for taking the time to measure that. My Snap-On MT-640 model's stationary point appears to be about 3 times longer than the Snap-On MT-335 model. The adjustment knobs are different lengths. From your photo I think the two brass posts are about the same distance apart. Do you or any other members know what is a satisfactory distance the spark should jump for a 6 volt coil to be considered good.


Thank you again,
Kyle

katy 02-10-2020 12:21 PM

Re: Coil Tester needed
 

1 Attachment(s)
Kyle, if you can borrow one of the cheap spark testers you could measure the spark gap at various voltages. May not be accurate, but should be close.

katy 02-10-2020 01:01 PM

Re: Coil Tester needed
 

1 Attachment(s)
Or try this chart:

Cape Codder 02-10-2020 01:15 PM

Re: Coil Tester needed
 

I just read an article that showed a coil can be tested with an ohm meter by checking across the two small posts and then checking from one small post to the spark plug connector.

This was for the Model A but did not give any spec's as it said "Determine the resistance using your multimeter and check to see if it's within the acceptable range".

What is the acceptable range on a 6V coil on the Model A?

fordified 02-10-2020 01:48 PM

Re: Coil Tester needed
 

Quote:

Originally Posted by katy (Post 1850689)
Or try this chart:




That chart is great! Thank you,


Kyle

Bob C 02-10-2020 03:08 PM

Re: Coil Tester needed
 

Quote:

Originally Posted by fordified (Post 1850454)
Bob, thank you for taking the time to measure that. My Snap-On MT-640 model's stationary point appears to be about 3 times longer than the Snap-On MT-335 model. The adjustment knobs are different lengths. From your photo I think the two brass posts are about the same distance apart. Do you or any other members know what is a satisfactory distance the spark should jump for a 6 volt coil to be considered good.


Thank you again,
Kyle


Kyle, I measured the gab when the knob is in the green area and it
is between 9/32" and 21/32".


Bob

fordified 02-10-2020 05:26 PM

Re: Coil Tester needed
 

Quote:

Originally Posted by Bob C (Post 1850728)
Kyle, I measured the gab when the knob is in the green area and it
is between 9/32" and 21/32".


Bob





Awesome!! Now I can fine tune the adjustment knob and test a few coils to see which ones are the best.
Thank you for taking the time to measure that gap. I'm sure it was not easy.
Kyle

d.j. moordigian 02-10-2020 05:52 PM

Re: Coil Tester needed
 

Quote:

Originally Posted by Bob C (Post 1849789)
I got one like this on Epay.

Bob,
I have one just like your's...BUT it's missing the neon bulb. Is there a number
on the bulb..OR do you know were I could purchase one?
Thanks,
Dudley

KR500 02-11-2020 02:27 AM

Re: Coil Tester needed
 

The units which need a bulb use a Geisler tube. They were used in distributor testers and also the ball point looking testers to test for spark. Snap On used to carry them in their parts books. Don't know who presently supplies them. I can supply instruction sheet and schematic for the various Snap on testers.


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