Hi, this is an old coil from an outboard engine, it is from the magneto. I need to test it to make sure it is ok, however i am a complete novice with this stuff, from what i have read online i am to test the resistance from A - B, I got the reading 1.9 ohms, however i am getting a reading from A - C of 0.5MΩ to 5MΩ, is this normal ?

 

Yes, that is very good luck that there is essentially no conductivity to "c". That means the clear enamel paint is in tact and no current is shorted to the "magnetic core". Hopefully, the low 1.9 ohm resistance is also good and no wire to wire short circuits exit and all turns of the copper wire are fully effective.

 

That resistance is typical for that type of coil, so it should be good to go.