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Discussion Starter #1
This 1966 has a brand new factory wiring harness.

I installed a 3g alternator along with the PA system that plugs in where the old regulator was on the firewall.

I have a Duraspark distributor with a GM module and no spark.

I am getting 12 volts at the + and - side of the coil with key on. When cranking I am getting 9.6 volts at + side of coil.

Please help.
 

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Perhaps your GM ignition coil or electrical internals are shot.
 

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This 1966 has a brand new factory wiring harness.

I installed a 3g alternator along with the PA system that plugs in where the old regulator was on the firewall.

I have a Duraspark distributor with a GM module and no spark.

I am getting 12 volts at the + and - side of the coil with key on. When cranking I am getting 9.6 volts at + side of coil.

Please help.
So, the Motorcraft pick up coil is triggering the GM HEI module.
Did it ever work? I'm wondering if the GM module is kaput. They need to be heat-sinked like a big dog.
Diagram is what goes where. If it's wired like that, it should work. (switcher is the negative side of the coil BTW)



748688
 

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Has it ever worked?

Before you get too tied up chasing the electrical system make sure the physical parts are ok. Is the rotor in place? Does it still spin when you turn the engine over?
 

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Discussion Starter #5
Long story it ran four years ago when I was trying to finish car for my son. Life got in the way adopting my nieces and here I am.

Heat-sinked the crap out of it in a empty Duraspark box. Ran extra ground using a jumper from #2 to a carburator stud.

Took cap off and engine cranked over rotor spun.

Is there a way to check these older gm modules?
 

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Long story it ran four years ago when I was trying to finish car for my son. Life got in the way adopting my nieces and here I am.

Heat-sinked the crap out of it in a empty Duraspark box. Ran extra ground using a jumper from #2 to a carburator stud.

Took cap off and engine cranked over rotor spun.

Is there a way to check these older gm modules?
They either spark or they don't. Use OE quality units only for those modules. There's a lot of crap out there masquerading
as quality automotive electrical.
You can test the pick up coil in the distributor with a digital meter. (Looked it up....... 400-800 ohms)
 

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Discussion Starter #7
Ok I'm going to get a new GM module and try that. The one I used had been laying around.

Thanks.
 

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Discussion Starter #10
Measured the ohms between the orange and purple wire coming out of distributor with key off and distributor cap off. 615 ohms seem low after seeing post above.
 

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Help please...install the OEM distributor, coil, and voltage regulator. It’s not rocket science. Have the distributor rebuilt and recurved by Dan at The Mustang Barn.
 

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Help please...install the OEM distributor, coil, and voltage regulator. It’s not rocket science. Have the distributor rebuilt and recurved by Dan at The Mustang Barn.
I agree, when properly set up the OEM ignition is as reliable as sunrise.
 
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