Should Ballast Resister be bypassed or not? MSD

My 66 Satellite with a good 440 runs very well, it has an MSD ignition installed by previous owner. In the paperwork it says to bypass ballast. Is that the norm to do? This is a working and running combination so before I do figured I'd ask.
I measured it has one in it that reads 1.9 ohms and thought since the stock point type one is only .5 or so would that be better or just gut the back of it as I've done with other ignitions and solder a 10-12ga. wire behind.
Thanks Ron

I’ve never left the ballast resistor on any of my MSD installations.

Depends on your coil.

Need to bee more specific when you say MSD Ignition

As in

MSD Distributor ? Or

MSD Ignition Box ? Or

MSD Coil ? Or

All of the above

All the MSD race and street ignitions that I've used , 404B to digital 7 non programable with a grid ,require you to eliminate the 12V resistor to the coil
The box controls the voltage pulse duration and voltage (WAY higher than 12.25V) to the coil for the multi spark feature
DON'T ask me how I know about the voltage to the coils

in my opinion this may be one of those "depends" questions. i don't use msd ignitions so my comments may only be relevant to a point. i have used ignition boxes were bypassing the ballast resister was either required or recommended. i never liked the way my engines ran without some resistance in the system. i'm not sure there was ever a performance advantage in my application by bypassing the resister. i know that measuring voltage at the coil with out the resister was pretty high,14-15+ volts using a good coil, your charging system should be checked for voltage output. i use an msd resister, .8 ohm, and have had good luck with them and the engine runs much smoother. i think 1.9 ohms is too much resistance. you may be getting less than 6 volts to the coil. i'm getting 10-11 volts with the msd resister. i'd try the msd resister first and if there's an improvement then take another step to no resister and see how you like that. another thing i'd do is measure plug wire resistance and plug resistance; that all stacks up. an msd requires some resistance. some prefer to put the resistance in the plug wires and plugs.

MSD boxes use battery power so no ballast's are used. It would not hurt to list what specific box/set up you have.

Try reading the installation instructions.

As far as the coil is concerned, the ballast resister circuit is no longer in play when using an MSD box. The coil gets energized directly from the box and with a 6AL IIRC the capacitor discharges 480 volts to the coil.

I suspect Cab has some first hand personal knowledge about this.

Kevin

OK did some more reading on this myself and know the direction I'm headed but to fill in the blanks:

MSD 6A,
MSD Blaster2 coil,
MSD spiral core wires.

The distributor itself is an MP electronic.

Reading my paperwork a few times I see it says no Ballast is needed (makes sense) but it also said you can leave the stock ballast. Reading about the coil it stated no Ballast needed so I guess they are saying if you are using all of our system remove ballast for our coil to work properly but you can also run this system with a stock coil and then the ballast can stay.

This was an existing set-up put in by previous owner so I would have thought any problems would have arisen already with this Ballast in place.
I am going to bypass it and test from there.

Thanks Ron

You should be able to figure it out by looking at how your system is wired. If the ballast resistor is just dropping the voltage to the MSD ignition box then it is hurting your performance and it probably isn't extending the life of the MSD box. The ballast resistor was originally designed to protect the points. It was then repurposed in the ECU era to protect the life of the coil. Look at how the last guy wired the ignition in your car. Does the coil get its voltage from the ballast resistor or is it coming from the MSD box?
You have to actually study how the system before you'll know what the last guy did. He might have bypassed the ballast but just left it there or perhaps he didn't read the instructions and he actually wired it up so the MSD box isn't receiving a full 12 volts. Anything is possible when dealing with backyard mechanics.

As far as I know the MSD box it drawing all power from the large wires they want going to the battery. The small wire is just a trigger source to activate the box. It will trigger off very low voltage so it really does not matter if you hace a resistor or not. I would prefer a direct battery voltage trigger.

OP didn't post any pictures or describe what the ballast resistor was doing so we're just guessing. The car would be wired with the ballast resistor in the power circuit for all we know.

No ballast with MSD stuff.

No the system is stand alone, the MSD goes straight to bat+ at starter solenoid and is grounded to the engine block. The dist. leads go right to the dist. and the the orange and black go to the coil so i would have to say the ballast isn't hurting anything as it is or am I incorrect on that?
Ron

It sounds like what some guys like to leave all the factory wiring installed just in case the MSD failed. You are correct in your description that is sounds like it's wired as a stand alone unit. You should be fine the way it's wired as long as you keep the connections clean and tight. loose or dirty connections are what kills MSD boxes

Gus

Unless MSD has changed their install instructions, the big black and red wires go DIRECTLY to the battery. I'm surprised it runs if you have it wired otherwise as I've seen it happen.

The wire that normally goes to the + on the coil is what is usually used to signal the on/off wire to the MSD box and that is why you need to bypass the ballast resister so that signal wire sees 12V.

Kevin

MSD6AL 2

Ballast Resistor: If your vehicle has a ballast resistor in-line with the coil wiring, it is recommended to bypass it



That’s why I was asking what box you where running or what/all components

So another words you want a full 12-14.5 Volts to the positive side of your Blaster 2 Coil with the engine running using the MSD6AL Box

Peace

In all my years this is the first car I have with an MSD so pardon my ignorance. But isn't having the large RED to the starter solenoid the same as running it to the battery terminal? I have the large BLACK to engine block and also a jumper from there to firewall.
The one wire I forgot to talk about is the small RED which I guess is the trigger you guys were speaking of and yes that goes to the blue wire that used to go to + at coil. So is that why it's best to jump the ballast resister?

Thanks Ron

X2

Orange
This wire connects to the coil positive (+) terminal. This is the ONLY wire that makes electrical contact with the positive coil terminal.


Is this wire directly going to the positive side of the coil ? Make sure this is the only wire

Small Red

This wire is responsible for turning the MSD On and Off. Connects to a switched 12 volt source such as the ignition key or switch

Yes here is exactly how it's wired in the attachment straight out of the MSD instructions except I am using the starter sol. stud for large RED and engine/firewall for large BLACK.
Ron

I know where your going now per instructions



Small Red says - From positive side of coil / From original + side coil terminal

In a Factory Mopar world , that might bee only 7- 9 volts positive side of coil , because of the Ballast Resistor resistance

However if you took it off the feed side , or ignition switch side of the Ballast Resistor , you would have the full 12 - 14.5 Volts going to the small red


So with that said , Take your volt meter , and supply that small red off the feed side/ignition switch side of the ballast resistor (Full 12 - 14.5 Volts engine running)
NOT the resistance side of the ballast resistor going to coil


And honestly

If you have any issues down the road , the LARGE Red and Black wires should bee directly fed off the battery terminals

Peace

OK makes perfect sense, tomorrow I'll see what the Fluke Meter says. Since it's the factory wire that used to go to + of factory coil it may be regulated by the ballast.
Thanks
Ron Sannino

You got it

No work on Labor Day

LOL

Peace

You would think 12v is 12v but I've seen it first hand on a hydraulic power pack unit that used a 2300 Ford, basically a Pinto motor for power. It had Duraspark ignition and they got tired of them failing so the owner had a CASCAR race team and lots of 6AL boxes in stock so he told the shop to swap it over. The tech wired it exactly like yours and it never offered to run. I told him it had to be wired directly but he was having none of it and sent out for another new 6AL which also refused to fire. Hooked it direct to the battery and vroom.

I have no idea why it matters but it does.

If you are using the blue wire for your switched 12v source to turn the box on and off, you need to bypass the ballast resister so the blue wire supplies constant 12v when switched on.

Kevin

Like Kevin said

If you want to keep the ballast resistor in place for that factory appearance and use that same blue coil wire
Or just wire it off the ignition switch feed side like I mentioned

Anyways , something like this first picture

Or

I removed the resistor element on the backside , and soldered in a heavier gauge wire from terminal to terminal
Then fill with two part epoxy

Looks factory and no one knows
Stole picture from internet , second picture

very easy to test voltage at the battery, coil, or resister with a multimeter.

Yes I've made ballasts before for a few FBO systems.

other then the trigger wire i usually think its best to not tie into ANY of the old wiring. Use new wires and wire the MSD completely independently directly to distributer, battery, coil. You can then wrap it and hide with factory harness, but keep the wiring independent.

I'm dealing with the ballast on my car too.I undrestand that the red trigger wire should have constant battery voltage on it ( mine is between 13.5 and 14 volts while running),what should I be getting on the orange wire at the positive side of the coil?

check voltage at the battery with engine running and it should be the same at the positive side of the coil if the ballast is bypassed.

MSD Tech



Next, lets review the coil wiring. The ONLY two wires that should be connected to the coil are from the MSD. The orange wire connects to coil positive while the black wire connects to the negative terminal. No other wires should be connected to the coil terminals! Also, do not touch or connect any tools to the coil. With the MSD connected there will NOT be voltage on the coil terminals unless the engine is running – and in that case there will be over 450 volts due to the CD technology of the ignition. Again, the only two wires connected to the coil are the MSD Orange, positive, and the MSD Black, negative.

MSD Tech

"One common question in regards to MSD Ignition controls is “Why isn’t 12V power on the orange (COIL +) wire?”
The main reason 12V won’t be present at coil + is because your MSD ignition is a Capacitive Discharge Ignition. Like all CD ignitions they use a large capacitor to discharge 420-480 Volts to coil + and coil – will normally be connected to ground. (That’s why you wont see +12V on coil +) "

Got it. Thanks for the reply.

You need to research what you are running, This is direct from MSD.

Have a look...
https://documents.holley.com/techlibrary_coil_compability.pdf