Re: [Chrysler300] correct 300H ignition coi voltagel
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Re: [Chrysler300] correct 300H ignition coi voltagel

Same story; that is about right ; DC resistance of a stock coil primary might be slightly different between 6 and 12 v , but both run in 6v  area w points closed. If you buy high performance coil has lower DC primary ohms volts will be even lower . Heavier current is equal to  more drop in ballast . Trade power for point life . It sort of does not matter 4-6 V ok . Spark energy is 1/2 L I squared . V is only needed to drive the I ( amps) into coil . L is set by turns and size . Not a lot of wiggle room to raise I . Stock set up optimized . Dwell is critcal as to reach I takes a certain time always , to fully charge coil . Barely enough at high rpm .. Why the two points in first place on letter cars . If set too loose high rpm miss coil undercharged. If too tight not clean break = high rpm miss . Coil tower must be spotless silicone grease under cup . Mopars are known for spark jumping under cup to primary terminals . Drove me crazy did not know that on 68 charger new car. Hi rpm miss .
Hope this helps . 

Sent from my iPhone

On Feb 27, 2016, at 9:34 PM, Michael Moore <mmoore8425@xxxxxxx> wrote:

Thanks John.
That was voltage through the ballast resistor with the engine not running. I measure 5.5 volts DC on a DC ammeter.
Thanks again, Mike

On Feb 27, 2016, at 3:26 PM, John Grady <jkg@xxxxxxxxxxxxxxxxx> wrote:

Because volts are moving  and load is pulsating on ballast the reading is kind of meaningless . 
But that sounds about right . If no skipping at high speed and dwell is ok ( that is what really matters --you need an old fashioned dwell meter to get dual points right  ) you are ok . When points  close , v drops through ballast --when open it goes up  to 12 no drop . You Are reading the average . By the way digital meters compound all this due to periodic sampling .  No good on cars . 
Sent from my iPhone

On Feb 26, 2016, at 7:54 PM, Michael Moore mmoore8425@xxxxxxx [Chrysler300] <Chrysler300-noreply@xxxxxxxxxxxxxxx> wrote:

Can someone p;ease tell me how to tell the diff between a 6v or a 12v coil?

I understand it should be a 6 v coil which gets 12v temporarily why starting by bypassing the ballast resistor.

I  have 5.5 volts running at the coil.

Mike Moore


Posted by: John Grady <jkg@xxxxxxxxxxxxxxxxx>

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