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Discussion Starter · #1 ·
There a still a couple things that confuse me regarding the wires to the coil.

From the diagrams I have....

One wire to the positive side of the coil comes from the starter solenoid " I " post.

and another wire to the positive side of the coil comes from the "on" post of the ignition switch via a resistance wire.

Is that right?

and then thare are 2 wires (+ and -) that plug directly into the distributer via an msd supplied connector.

I'm using an MSD distributer and coil for my 289...

thanks

g
 

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Are you using an MSD box? If so, there is no need to go to the I terminal of the solenoid because the coil is powered by the box with an MSD system, not the resistor wire.

Otherwise, using the I terminal from the solenoid allows a full 12 volts to the coil during cranking by providing 12 volts from the solenoid instead of the 8-10 volts from the resistor wire that normally runs the coil.

Greg
 

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I think you're on the right track.
On a Ford ignition system the coil + is fed through a resistive wire in the wiring loom back up in the dash. That limits the current to the coil to prevent it from burning out.

During start, the battery is pushing the starter and with that resistor wire in the loom it would drag down the spark so the "I" terminal jumpers over the resistor during start to provide direct battery voltage.

I assume that you have an MSD ignition box to go with your new distributor or is this the new all-in-one distributor? It makes a big difference.

With an MSD box, the dist. becomes just a 'trigger' and no coil current runs through the 'points'. The box drives the coil entirely and has a direct 12V input for controlling current into the coil. The factory resistance wire becomes moot. However...if you bought the all-in-one you might need to consider the resistance wire...

Let me know the complete system you have and we can set you straight.
 

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Dang...GregP is fast! He beat me to the punch.
 

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Discussion Starter · #5 ·
You guys are fast...i wrote my question.....then i sat down to eat my pancakes....and i turn around and there are 3 replies!!! Wow...

I have one of those "Ready-to-Run" distributers that gives me the option to use the box or not. Since right now all I'm doing is getting ready to run the engine on my test stand ( i have another thread on that subject) I'm wiring the distributer to NOT use an external box. Later when I've got the engine installed...I'll be geting the box.

Where would I get one of those resistance wires?

thanks again....

g
 

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First, I would find out if MSD needs a resistance wire in the loom.
If you're running a factory loom then you should be okay. If not, you can add an external balast resistor (available anywhere online...).
 

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Discussion Starter · #7 ·
My msd coil came with a ballast resistor that I'm supposed to use if I used my coil with a points distributer.

I'll get on the msd website and ask them if I need a lower voltage to the coil after the engine has started....

thanks

g
 

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You only need the resister wire or ballast resister if you run points. Electronic ignition systems need the full 12VDC for proper operation.
 

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I agree with Patrick. I deleted the resistance wire on my 69 mustang when I ran a new Crane digital distributor and Fireball ignition box. I just ran a new 12V source from the ignition switch and terminated the resistance wire that was already neatly taped up in the loom. ......John
 

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You only need the resister wire or ballast resister if you run points. Electronic ignition systems need the full 12VDC for proper operation
Hmmm...that's really not good advice. Mallory Unilites need the resistor therefore making a global statement like that contradicts the manufacturer.

Just do what the manufacturer says...
 

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I have the exact same distributor and did some research to make sure, and you do not need nor want a resistance wire or ballast resistor with the RTR distributor... just hook it up straight to 12v. Been running my 289 like that for over 10K miles and no problems whatsoever. But as allenman said, not all electronic distributors are like that, the Mallory Unilites need the ballast resistor to limit the coil current and keep them from burning up.
 

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On 2006-12-04 15:39, allenman85 wrote:
You only need the resister wire or ballast resister if you run points. Electronic ignition systems need the full 12VDC for proper operation
Hmmm...that's really not good advice. Mallory Unilites need the resistor therefore making a global statement like that contradicts the manufacturer.
I'll rephrase. GOOD electronic ignition systems do not need a resister wire or ballast resister
.
 

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On 2006-12-04 23:48, pbrown wrote:
On 2006-12-04 15:39, allenman85 wrote:
You only need the resister wire or ballast resister if you run points. Electronic ignition systems need the full 12VDC for proper operation
Hmmm...that's really not good advice. Mallory Unilites need the resistor therefore making a global statement like that contradicts the manufacturer.
I'll rephrase. GOOD electronic ignition systems do not need a resister wire or ballast resister
.
Good? I've had the same Mallory Unilite in the Bronco's 460 for 12 years, running a Mallory ProMaster coil... never had a single problem with it. Wouldn't that be considered good?
 

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Good? I've had the same Mallory Unilite in the Bronco's 460 for 12 years, running a Mallory ProMaster coil... never had a single problem with it. Wouldn't that be considered good?
Just sold mine after 20 yrs...working great so I vote YES!
 

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There is good reliable which I have no dought that the Mallory is and then there is good for high performance. Any ignition that requires reduced voltage at the coil and thus reducing the available spark energy and coil recharge time is not good in my book. I'll stick with my MSD stuff any time.

A Mallory used with a performance ignition box like the Hifire or MSD 6al is a different story. That would be fine.

I have nothing against Mallory. I thought I would just ruffle a few feathers
.


_________________
Patrick Brown

62 Falcon - 331 stroker - C4

<font size=-1>[ This Message was edited by: pbrown on 12/6/06 5:36am ]</font>
 

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You probably have a point there... and I will admit that while the Mallory has been great for my 4500rpm mild 460, I went with MSD for my 7500rpm 289
 

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The 6 & 7 MSD boxes output the correct voltage for the coil - you put power to the box and it has internal resistors that correct it for the coil.
 
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