I have removed the ignition coil from my 96 Road King.. I have an ohm meter and want to test to see of the coil is bad. The coil is a Crane "HI INTENSITY COIL". It has 3 posts ( - + -) above where the spark plug wires plug in to the coil. I'm just not sure how to test this thing.

 

measure from the center post to one of the others. it should be 3 ohms (don't quote me). but if you are tracking down a failure, coils will often test out fine when cool, but fail when hot.

 

A megger can help you inspect the insulation of each coil between high voltage and +/- connections. Pick one that's in the 500V range. As you warm up the coil with a hairdryer to simulate temperature change you can detect a trapped air pocket during degassing of the putty.
If you don't already have one, search " Megger, insulation tester 500V" on eBay.

 

All electric devices are in one of two categories, 1 = switch, open or closed. 2 = work or load which is resistance.

Since a coil is not a switch....

Measure resistance between the positive and negative posts, you should read resistance, if it reads open, it's bad, if it reads 0.000 it's bad.

Now, as mention by another member, it could fail as it heats up. if you want specific ohm readings for your particular coil, you can check the specs.


Old school test, apply 12vdc + to positive, touch 12vdc – to negative side with a sparkplug attached and grounded, you should get a spark.

You can buy a few coils for the price of a megger.

 

http://www.wikihow.com/Use-an-Ohmmeter

http://www.autos.com/car-maintenance...-ignition-coil

 

I paid less than $60 for mine.

 

I paid a over a grand per unit for my technicians, not sure what you purchased but we buy quality tools for our work, I couldn't buy the cables for $60

More power to you.

I am not sure why a megger would be required to check a common coil, now if you had one and wanted to play around, sure, why not. We use them for ground impedance.

 

Two different but complementary worlds in terms of safety
When I chase isolation breakdown, I use a high DC voltage source with a galvanometer (in series). I have one floating coil megger and one 'fancy' Chauvin-Arnoux with a zero spring return. Both have their built in magneto so they can sit on the shelf for ages because they don't rely on batteries. I'm looking for a variation of hundreds of megohms, so cable quality is not critical as per your domain.
From military epoxy potted transformers to oil burner ignition transformers, extension power cords to kitchen toasters these meggers do the job.

 

Lightening protection for radio equipment here. just making sure it goes to ground and after it does, making sure it will do it again.