[AT] Questionable ignition coil

[szabelski at wildblue.net]

You can check the resistance of the two internal coils to see if they’re open or not, or if there’s an internal short. But to do this you need to know what the base resistance is that you should be checking for. That means that you have to be able to find the specs for your particular coil. On older coils that may not have any type of manufacturer marking, or may simply have a good coating of surface rust, you probably won’t be able to determine the manufacturer. You can try to use general values, but that won’t guarantee anything.

You can find directions for testing coils on line by searching on something like “testing automotive coils”.

Even if you can find some kind of marking, part number, etc, there’s no guarantee that you will be able to identify the manufacturer. Last time I had to put a new coil on the H I went to NAPA with the bad coil. It had a NAPA sticker on it and you could read the number 905 stenciled on the side The counter guy could not identify the coil. We both went through catalogues looking for a coil with the number 905, couldn’t find it. The counter guy finally gave up and called a coil manufacturer  ( I think it was Echlin ) and told him what we were looking for. The answer was that we wanted a 1C14 coil. When the counter guy brought the coil to the counter, we opened up the box and saw that the coil had a NAPA sticker on it......and the number 905 stenciled on it. It was the exact same coil. There was no marking on it that indicated 1C14 or that indicated the manufacturer.

I kept the box from the new coil just in case I ever have to replace it again, or I somebody else should happen to need a new coil for their H.

Good luck!

Carl

----- Original Message -----
From: Gilbert Schwartz <vschwartz1 at comcast.net>
To: at at lists.antique-tractor.com
Sent: Tue, 05 Nov 2019 20:19:38 -0500 (EST)
Subject: [AT] Questionable ignition coil

I would like to try and delve into the wide knowledge and expertise of the members within ATIS.
Is there any acceptable method of determining if an ignition coil is good short of installing it on a running engine. Our 1949 AC G would not start a few days ago after being parked for a short period of time. A quick observation determined the contact points were beyond use. I went to the local auto parts store and was advised I probably should replace both the points and of the condenser because they felt like that condenser went first and it caused the points to burn up. With this information I also purchased a new coil even though I wondered if the coil was a bad.
Bottom line; Is there any way to bench test a coil? We have several used coils laying around here of questionable viability. I would like to pitch them if they aren't any good.
I appreciate anything you can tell me.