24volt Coils Again

Cacti_Ken · Post by **Cacti_Ken** » Fri Sep 22, 2023 7:50 pm

I recently ordered and received 2 coils. 24 volt coils that are assumed to be the best after market coils today.
After receiving the coils I did a resistance check on them.
The primary windings I found had no resistance, Open circuit.
The secondary windings had 12.xk and 13.xk ohms

So with that, I was reluctant to go any further without contacting the supplier first.
Supplier is confident they are good and gave me the go ahead to do the test with 24 volts.
I put the coils in a spare distributor. I got a spark out of the distributor cap to ground.
It is a strange thing to me.
The primary even measured a capacitance valve in pico Farads across the primary on another meter.
Go figure!
I don't have a high voltage probe for my oscilloscope to measure the output voltage.

Post by **wesk** » Fri Sep 22, 2023 9:24 pm

You sure you had the ohm meter on it's low setting and the batteries in it are good?

Cacti_Ken · Post by **Cacti_Ken** » Mon Oct 02, 2023 4:26 pm

Sorry it's taken me till now to reply.

I have an older model Fluke 8020B which has push buttons for the different modes and ranges. The 200 ohm range is the lowest range. A new 9v battery, I measure 35 ohms across a 33ohm resistor. 1% tol. I still could not measure any resistance on the primary.

I ordered a new Fluke and also an analog meter.
The Fluke is Auto range. 33ohm resistor shows 33 ohms. It will not show any resistance in the primary either.
As well the analog meter with a brand new battery 1.6v, on x1 scale reads 32 ohms and won't show any resistance on the primary either.

I guess even though it some how had a spark when I tested on a spare distributor, I'm going to install them in the distributor in the jeep and see if the motor runs as well as it currently does.

Cacti_Ken · Post by **Cacti_Ken** » Fri Oct 06, 2023 4:31 pm

Wes, I have come to the conclusion that I am probably not measuring in the correct places on the coil for the primary. I tried following one of your photos of the coil for the measuring of the primary. I believe I am wrong.

I installed the coil in the Jeep distributor and the engine fired right up. I went for a test drive and the coil performed very well.

RonD2 · Post by **RonD2** » Fri Oct 06, 2023 5:22 pm

If it helps, here's a quick 3 minute video on how to measure coil primary and secondary winding resistance: https://www.youtube.com/watch?v=P9EpazLAIQs

Cacti_Ken · Post by **Cacti_Ken** » Fri Oct 06, 2023 5:53 pm

Thanks Ron. I do feel embarrassed.
I wasn't measuring across the post.
The resistance is 12 ohms across the post of the one that I haven't put in the jeep yet to test.

The one I did install ran really good.