I also think "Bubba" also posted that if a coil is run one polarity (correct or incorrect) for a while, the iron core takes a magnetic "set" that can be deleterious to the future efficiency of the coil, especially if the polarity is switched. This is way beyond me, bit I'll take him at his word on this.
I can't tell by pictures... size,LxW, it looks like it comes apart...good thing. See if you can carefully do that. I assume it's full of tar. If so, unless you could carefully heat it (boiling water?) once apart (step 1...check to see you may luck out and an obvious bad connection!) otherwise you'd have to remove insides. If you have a clean empty case is it 6 volts or converted to 12 volts? If you can fit the correct voltage coil into that case, then wire the 3 connections the same, reassemble, you'll have a working coil in that case. Sent from my SM-S320VL using Tapatalk
When I took automotive in mid 70s the instructor said that, reversing polarity will work but lower output. It needs to be correct. Sent from my SM-S320VL using Tapatalk
I would think the easiest way to test a coil is to put it in your car and see how it works. It only takes a couple minutes. Bring along the old coil just in case! It's like a car battery - you can get a test rig for it, but my test is always to throw it in one of the fleet and use it for a few days.
I agree. A good mechanic friend of mine has a known good one of each shelf. That's how he troubleshoots quickly...he will pop in a distributor, alternator, etc. in a few minutes to test. None of that test stuff is for sale, and he marks them. Sent from my SM-S320VL using Tapatalk
This has been an interesting and informative thread. When I was a kid I would swipe the vibrator ( settle down boys) out of my dads old car radios which is a high speed switch and acted like the points. I would connect up a coil and a 12v source and really impress the other kids by throwing a spark to one of the terminals. Cant recall all the details but it would shock the hell out of you.