Old school coils were just two copper winding, primary was a couple hundred turns of wire. Ohm reading 1 – 5 ohms. Secondary was 10k turns of very fine hairlike wire Ohms 100 – 2k ohms. But the engineers couldn’t stand it. They added electronics inside the guts. Cant do simple tests anymore. I bought 4 ignition coils for my Rav4

 https://www.arboristsite.com/threads/coil-testing-with-multimeter.376674/