Go Back   The Ford Barn > General Discussion > Model A (1928-31)

Sponsored Links (Register now to hide all advertisements)

Reply
 
Thread Tools Display Modes
Old 02-07-2020, 05:27 PM   #1
v8nut
Senior Member
 
v8nut's Avatar
 
Join Date: Dec 2010
Location: San Jose, CA
Posts: 157
Default Coil Tester needed

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.
Attached Images
File Type: jpg s-l200.jpg (5.4 KB, 128 views)
v8nut is offline   Reply With Quote
Old 02-07-2020, 07:55 PM   #2
redmodelt
Senior Member
 
redmodelt's Avatar
 
Join Date: May 2010
Location: Portland OR
Posts: 5,070
Default 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
__________________
I know the voices aren't real but damn they have some good ideas!
redmodelt is offline   Reply With Quote
Sponsored Links (Register now to hide all advertisements)
Old 02-07-2020, 07:57 PM   #3
VinceBlack
Member
 
Join Date: May 2017
Location: Kansas
Posts: 40
Default Re: Coil Tester needed

I made one using an old distributor and spark plug.
VinceBlack is offline   Reply With Quote
Old 02-07-2020, 08:35 PM   #4
v8nut
Senior Member
 
v8nut's Avatar
 
Join Date: Dec 2010
Location: San Jose, CA
Posts: 157
Default 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.
v8nut is offline   Reply With Quote
Old 02-07-2020, 08:59 PM   #5
Bob C
Senior Member
 
Join Date: May 2010
Location: So Cal
Posts: 6,861
Default Re: Coil Tester needed

I got one like this on Epay.
Attached Images
File Type: jpg MT-335.jpg (44.9 KB, 162 views)
Bob C is offline   Reply With Quote
Old 02-08-2020, 11:15 AM   #6
holdover
Senior Member
 
Join Date: May 2011
Location: SW Virginia near the Blue ridge Parkway
Posts: 629
Default 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
holdover is offline   Reply With Quote
Old 02-08-2020, 11:53 AM   #7
katy
Senior Member
 
katy's Avatar
 
Join Date: Jun 2015
Location: Alberta, Canada
Posts: 2,536
Default Re: Coil Tester needed

https://model-a-ford.org/resources/t...n/coil-tester/
__________________
Play it again Sam.
katy is offline   Reply With Quote
Old 02-08-2020, 07:33 PM   #8
rotorwrench
Senior Member
 
rotorwrench's Avatar
 
Join Date: Jun 2010
Location: San Antonio, Texas
Posts: 11,561
Default 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.
rotorwrench is offline   Reply With Quote
Old 02-09-2020, 09:23 AM   #9
fordified
Junior Member
 
Join Date: Oct 2011
Location: Holt, Michigan
Posts: 20
Default Re: Coil Tester needed

Quote:
Originally Posted by Bob C View Post
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
fordified is offline   Reply With Quote
Old 02-09-2020, 01:53 PM   #10
Bob C
Senior Member
 
Join Date: May 2010
Location: So Cal
Posts: 6,861
Default 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
Bob C is offline   Reply With Quote
Old 02-09-2020, 03:06 PM   #11
v8nut
Senior Member
 
v8nut's Avatar
 
Join Date: Dec 2010
Location: San Jose, CA
Posts: 157
Default 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
v8nut is offline   Reply With Quote
Old 02-09-2020, 06:13 PM   #12
fordified
Junior Member
 
Join Date: Oct 2011
Location: Holt, Michigan
Posts: 20
Default Re: Coil Tester needed

Quote:
Originally Posted by Bob C View Post
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
fordified is offline   Reply With Quote
Old 02-10-2020, 12:21 PM   #13
katy
Senior Member
 
katy's Avatar
 
Join Date: Jun 2015
Location: Alberta, Canada
Posts: 2,536
Default Re: Coil Tester needed

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.
Attached Images
File Type: jpg coil tester.jpg (24.4 KB, 9 views)
__________________
Play it again Sam.
katy is offline   Reply With Quote
Old 02-10-2020, 01:01 PM   #14
katy
Senior Member
 
katy's Avatar
 
Join Date: Jun 2015
Location: Alberta, Canada
Posts: 2,536
Default Re: Coil Tester needed

Or try this chart:
Attached Images
File Type: jpg voltage-vs-gap.jpg (23.8 KB, 53 views)
__________________
Play it again Sam.
katy is offline   Reply With Quote
Old 02-10-2020, 01:15 PM   #15
Cape Codder
Senior Member
 
Cape Codder's Avatar
 
Join Date: May 2010
Posts: 1,050
Default 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?
Cape Codder is offline   Reply With Quote
Old 02-10-2020, 01:48 PM   #16
fordified
Junior Member
 
Join Date: Oct 2011
Location: Holt, Michigan
Posts: 20
Default Re: Coil Tester needed

Quote:
Originally Posted by katy View Post
Or try this chart:



That chart is great! Thank you,


Kyle
fordified is offline   Reply With Quote
Old 02-10-2020, 03:08 PM   #17
Bob C
Senior Member
 
Join Date: May 2010
Location: So Cal
Posts: 6,861
Default Re: Coil Tester needed

Quote:
Originally Posted by fordified View Post
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
Bob C is offline   Reply With Quote
Old 02-10-2020, 05:26 PM   #18
fordified
Junior Member
 
Join Date: Oct 2011
Location: Holt, Michigan
Posts: 20
Default Re: Coil Tester needed

Quote:
Originally Posted by Bob C View Post
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
fordified is offline   Reply With Quote
Old 02-10-2020, 05:52 PM   #19
d.j. moordigian
Senior Member
 
d.j. moordigian's Avatar
 
Join Date: May 2010
Location: Fresno, Ca.
Posts: 3,595
Default Re: Coil Tester needed

Quote:
Originally Posted by Bob C View Post
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
d.j. moordigian is offline   Reply With Quote
Old 02-11-2020, 02:27 AM   #20
KR500
Senior Member
 
KR500's Avatar
 
Join Date: Mar 2012
Location: Addison,ll.
Posts: 375
Default 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.
KR500 is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Sponsored Links (Register now to hide all advertisements)


All times are GMT -5. The time now is 11:27 PM.