There are 12 volt coils, and there are 12 volt coils.

Coils normally marked as 12 volt are made to have a resistor in front of them. Other 12 volt coils have the resistor built into the coil.

Rambler was one of the few that used a coil that had the resistor built in.

glad you got it up and running.

Thanks! Not sure if you've been keeping up with the old thread I started a couple of months ago about the overcharging issue but after installing the new coil the voltage has dropped down to normal levels and it's not overcharging anymore!!!! I'm talking between 13.2 - 14.2 volts from idle to acceleration!!!!
Could it be the coil or a connection on the coil was the issue and the reason it was overcharging??? I don't think it's a coincidence but maybe it is...

not likely.
it is down stream of the splice that supplies power to the vr sensing line.
more likely some wiring you messed with, a connector or whatever got connected better.
till you find it, I would continue the bypass, because a good bounce, or road vibration could make it go bad again, and you don't want to see a spike while driving.
had one go out like that while driving and it vaporized 2 inches of copper and about 5 inches of insulation under the dash. showed something crazy like 100 volts output.

"had one go out like that while driving and it vaporized 2 inches of copper and about 5 inches of insulation under the dash. showed something crazy like 100 volts output."


and i'll just kinda' guess all the "magic smoke" escaped, causing a great deal of consternation..............

have you Ohmed out the coil? possible internal short pulling the Voltage down
You could always reinstall to see if the issue recurs But sometimes at the end of a long journey it's best to leave things alone

the smoke pouring out from under the dash at 55 with all the windows down was quite impressive, I will say.
I don't think I have ever pulled over that fast before and jumped out of a car.

the fact it still was running and everything seemed to be working was amazing.
I was near some small town in podunk and a garage was on main street and they offered to take a look, since the car wasn't on fire. lol.

i'll bet the guy that come up with the invention to "re-install magic smoke" will make a fortune !

here ya go, Do be aware there are different sizes depending on the amount needed. The first pic shows the injector kit . Also there are newer versions that are claimed not to be as good as the original. Last verify country of origin as there are some knockoffs that may work or require a complete rewire after using BTDT 🧨🎆🎉💥💥👎🏻🤫🤣🤣🤣🚀

No good.
These are for positive earth systems.

Perfectly fine if you turn the container upside down before injecting the smoke. Doing so reverses the electrons polarity 🤫🤣

i always knew the "magic smoke" solution was out there, but i have never seen the tool used to install it.

Ugh...... I'm back and I'm not happy!
So this van is having some serious electrical issues!
It's doing the same thing! It's not firing with the new coil and there's no spark coming out of the ignition cable from the coil! I checked the voltage at the positive side of the coil and it's at 12v again!!! No bypass! I took that out!
I've only driven 3 miles with the new coil! Could the coil really have burnt out after such a short drive???
So I thought we had figured out that the bypass(temporary install due to an overcharging issue which I started a thread for a few months ago) was feeding the coil side of the resistor 12volts and that's what burnt out the coil and I removed the bypass and got the voltage to the plus side of the coil back to around 8.4volts but now It's back to 12volts at the coil and I'm not sure why because I took the dang bypass out!
So something isn't doing it's job and it's sending 12v to the coil! I suspect the starter relay! The wire goes from the resistor to the starter relay and from there to the coil! It was at 8.4volts when I installed the new coil! Since then I drove 3 miles and now the coil is getting 12v, no bypass and no spark!
Bad starter relay?

no, the starter relay always gives 12 volts.
ballast resistor usually goes open when bad, but I guess I would start with a new coil and a new ballast resister just in case.

or rewire the entire circuit. As I recall, your pictures showed a need for a good pair of wire cutters. no offense meant just stating my observation.

I have a new coil and ballast on the way!

Ok so it's obvious the ballast resistor is bad!
I did a bunch of resistor tests a few months ago when I first started working on the whole 'overcharging' issue the van was and is still having because of a voltage drop somewhere which there is a thread for and I posted a few pictures with all the readings and one of the readings for example was 13 volts going into the resistor and 8.25 volts coming out, with the key ON and bypass engaged to both sides... The reading I'm getting now with the key ON and no bypass is 12.3 going in and 12.2 coming out!
I had previously mentioned that I removed the bypass from the coil side of the resistor but what I didn't understand at the time is that it didn't matter that I did that because the power wires going into the ballast are part of the same circuit and I was still running the bypass to the voltage regulator side of the resistor and even though only one side was being fed battery power through the bypass both sides were getting that same voltage!
Even with the bypass the battery was still getting higher than normal voltage so if I have a wire coming straight from the battery to the resistor and the battery voltage reading is between 13.8-14.8 when driving that would mean the resistor was getting that same voltage and that would mean I fried the resistor with the bypass! Is that correct???
I know I need to figure out that voltage drop which was causing the voltage regulator to overcharge the batter which is why I ran the bypass to the resistor in the first place and that's what's caused the system to fry the coil and the resistor!
Am I on the right track here?

I know what you're referring to.... Here's a clear picture of that mess... It's part of the battery isolator and non of those wire are connected to anything! Here's a picture of that, take a close look!

yeah, the voltage should not be the same coming in and going out.
I would still bet some other wiring issue, but getting a new ballast is a place to start.
like I said, they normally fail open, but I wouldn't say it is impossible to fail with no resistance.
if after changing it you still get 12 volts to the coil I would say you have other wiring to chase down to make sure something upstream at the bulkhead or the splice isn't wired wrong, burned through and shorted or whatever.

The Ballast resister will not reduce the voltage until it gets hot. It is the heat that causes the resistance. If you are checking the resistance while the resister is cold, it will read battery voltage. With in about 30 seconds of having voltage pass through it,, the resistance should start to increase. After the resister has warmed up, you should be able to see the voltage reduction.

3 miles on a coil with 12 volts should not be enough to cook a coil, unless it was nearly junk to start with. I'm betting the coil is not your problem.

My guess is you have a different problem, but I have no idea where to start looking, given the history of the van.

At this point, I believe I would test the electronic pickup in the distributor. There is a test procedure, but I would have to look it up and don't have time to do that right now.

There is a way to test the coil as well to see if it will produce a spark, but I'm not sure how to communicate that to you. All I can say is with the old points, the negative wire off the coil grounded through the closed points. When the points were closed, the coil was energized. when the points opened, the coil would shoot off a spark. Back in those days, if you closed the points, with 12 volts to the coil, then opened the points with a screw driver on the points arm, the coil would produce a single spark spark each time you let the points close, then opened them again. That entire process of closing the points and opening them to have the coil give off a spark only takes a matter of seconds. Opening the points broke the 12 volt circuit ground and caused the coil to create a spark.

You should be able to use a test wire connected to the negative side of the coil, have a good coil wire (the one that goes to the center of the distributor cap) in the center post of the coil resting on a good ground with a little less then a 1/4" air gap to the ground, where you can easily see the spark jump. With 12 volts going to the positive side of the coil, and the test wire connected to the negative side of the coil, and the bared other end on a good ground, with a coil wire in the coil terminal, position yourself where you can clearly see the open end of the coil wire and the nearby ground (1/4" or less away), watch for the spark and remove the test wire from the ground. The spark should happen immediately. If the set up is correct, every time to connect the test wire to ground a few seconds and remove it, you should get a spark. With the motor running a 1,000 rpm, that spark is happening 1,000 times each second.

Test the coil. Test the distributer pick up. If both test good, test the plate the distributer pick up plate is screwed down to and make sure it has a good ground. if all 3 test good, the problem is likely a bad brain box for the ignition, or a wiring problem some place. .

I haven't changed the configuration of any of the components or wiring since I've had the van... I've owned it for at least 12 years and have replaced most electrical components under the hood and signal relays etc... Just parts swaps, simple stuff like that...
It's possible the previous owner switched some stuff out(changed the configuration of the wiring) but I assume I would've ran into the issues I'm having now years ago if that was the case...
I'm discovering a few things about the van that just don't seam right like the ballast resistor for example... In the wiring diagram out of the Haynes manual it's showing a single wire resistor(one wire in and one wire out) for my year van and taking a look at the diagram for vans years 1971-1976 and 77 and 78 show the dual resistor which I have in my van and mines a 79'....
The splices haven't been rewired or look bad and I've tested all these circuits for current and it all seams fine! The bulkhead is fine as well!

Remember, my van still has that overcharging issue that I started a thread for months ago and I did a pretty thorough inspection of all the connections in the bulkhead and tested the voltage on both side of the circuits in question....I still haven't had time to figure that out and I'm assuming this coil/ballast problem may be related to that in some way so I think the most important and obvious place to go is to revisit that thread and get that taken care of! I ran the bypass from the battery to the ballast so that I could still drive the van to work temporarily while I got my daily driver fixed...