Simple question, with the ignition key in the run position, I have power on both terminals on the ballast resistor, is this normal? I'm fighting all kind of issues on my ignition and fuel so i'm starting with ignition.Thanks.

Yes. it will also be present in the start position but the resistor is bypassed putting full voltage to the coil.
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How to test a voltage regulator?

In the START position, U should have 12V on both ballast resistor terminals.
In the RUN position, U should have 12V on the ballast resistor input terminal and 8-9V on the output terminal.

Just my $0.02...

That would depend on what style regulator is has, you know the first question a parts store will ask you? Year, make and model.

The FSM will cover how to test that.

Get one

https://mymopar.com/service-manuals/

The 8-9V will only be when current is moving through the resistor

most parts stores can also test the regulator for you. Year , make, model and a voltmeter will help as well. Check your grounds

What kind of issues? Maybe we can help.

Hmmm...
U are kinda on the right track...
Attached file of a wiring schematic for a basic ignition system should help U better understand how things work..

Just my $0.02...

Since the original question was concerning an electronic ignition ballast resistor, the above diagram for a points resistor isn't correct. You need to post the diagram for an electronic 4 post resistor.

Where did the question of a voltage regulator come from? Different part for a different purpose.

Forget about the voltage regulator...
Different part, part of the charging system of the alternator and battery.
Note that certain Mopars depending upon the year had an electronic ignition system using a (2) terminal ballast resistor, while others used a (4) terminal ballast resistor...
Note the (4) terminal ballast resistor was used in the early days to protect the power transistor in the ignition module, later on higher voltage capable transistors were used in the ignition module so the second resistor part of the (4) terminal ballast resistor was not required. As requested here is a basic schematic of an electronic ignition system using a (4) terminal resistor. If U have any more technical questions just PM me, no need to take up additional bandwidth.

Just my $0.02...

I never saw a post that said electronic ignition? It is important to know wether you are working on points, original 5 pin ECU or later 4 Pin ecu system.

Second, as mentioned by earlier, you need a basic understanding of electricity also. When voltage is present, but no load being supplied. No current flow. Voltage readings will be at the Source voltage. Battery at what ever voltage it is. Only when current is flowin through the load (resistor in most DC circuits) will you see corresponding voltage drops across the load.

The Service manual really has some good trouble shooting for electrical. Good battery, Good ignition switch, good bulk head connections, etc....

Describe your symptoms that are bad, and I am sure folks can help you isolate issues to check.

This is on a 68' Barracuda 410 with Mopar orange box that I just put on. I had the MSD 6AL Digital system on . I did all of the test from info online for the MSD and it proved to be bad. Put the orange box with Mopar distributor and I'm having the same issue,,, no spark at all. Battery good, ballast resistor test good. Maybe distributor not grounded good. I'm sure it's something simple that I am overlooking.

How did you test the resistor?

Forman open or ?

Recently had a no start/no spark situation. Tested the ballast - it had voltage at the wire coming in, where the red wire for the MSD was attached. I assumed that was good enough.

I “ tested “ the ballast and it showed continuity. But the core was cracked. Replaced it and the vehicle started right up.
Looking at it again, I should just bypass the ballast.

I tested ballast for voltage with key in run position, forgot exactly the numbers but it was lower numbers coming out. I did jump the two ballast connectors for a try, but same results, no spark.

2 or 4 post resistor? Did you check it with the terminals disconnected? If they are connected you are reading voltage threw the resistor. Ignition on one will have power and cranking the other will have power.

Just a suggestion...
Be sure and check the reluctor gap inside the Mopar electronic distributor, it should be 0.008 using a brass feeler guage...
We have had new out-of-box distributors this is set too wide, and the ignition module will not fire...

Just my $0.02...

not sure If you were responding to me or the OP,

Thanks for all of the help my buddies. My little brother found a test for the coil that I thought I had done. Which I know I did but must have not read meter correctly. Found coil to be bad. I had an old coil hanging around and threw it on and it fired up. I’m not going to use this old coil. Y’all have any recommendations for street strip. 410, pump gas using orange box setup may put the MSD 6AL Digital box and distributor back in?

If things don't have to look stock, the best coils I've used are the early '90s F150 epoxy-filled units.
Local auto parts should have them under $40 - or spend double that for MSD red paint.
They use a pigtail - also sold at auto parts stores, about $8 - and use an HEI terminal, so you'll need a matching coil wire for a few bucks more.
I fab a small mounting bracket for them from aluminum angle stock.
Best coils I've used, and can be mounted in any orientation you like.

For stock-appearing street cars, I use the restoration coils, and they work fine with the (hidden) orange boxes & OEM ballasts.