Anybody know where the actual ground connection is for the coil?
I get 12 volts on the positive side when I check to good ground. But on both wire terminals it fluctuates from 3 volts down to .1.
Can I reground the coil somewhere else?

Thank you in advance,
Jeff

FWIW it is a 460 in a E-350 chassis for a Winnebago motor-home.
I have replaced all ignition wires, coil cap rotor. Each one seemed to fix the problem for a while. It has run fine every once in a while but then won't start.

 

The ground side is the trigger for the coil to fire. It grounds through the ignition box.

make sure the coil BRACKET is got a clean connection to the engine and check the ignition box grounds (actually ALL the grounds are suspect)

 

sounds like possibly a bad coil if grounds check out good. should have like .7 on primary and like 9-12k on secondarys.

 

I see the OP says he has 12 volts on the +side of the coil.
Did you mesure that, or use a test-light?

Should'nt it be more like 6.5 volts? Doesn’t the Ballast resistor drops the voltage ?<?xml:namespace prefix = o ns = "urn:schemas-microsoft-comfficeffice" /><o></o>
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Yes with a multimeter.
It was 3 volts fading to .1 using the positive and negative connections.
I measured 12 volts between the positive and a good ground.
Is that in the coil or at the other end of the wire?

 

I checked the voltage on the + side of the coil to ground and it is 6.5 volts.<?xml:namespace prefix = o ns = "urn:schemas-microsoft-comfficeffice" /><o></o>
I thought that the electronic ignition used 12 volts to the coil, so we check another vehicle with the motorcraft ignition and it was 6 volts.<o></o>
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This was on a 1987 460, carbureted, MoHo. <o></o>

 

Thanks.
Rebuilt the Carb today, of course it started right up and idled for 7-8 minutes then died. Wouldn't restart, but at least it won't catch on fire now.
Took out the coil and it checked out fine.
Just looked at the Duralast/Control Module - Ignition online and for 27 bux should have just bought one.
I am guessing that is the next step in the electoral system.

 

Where did you get the spark box for 27 bucks?
I'll carry a spare for that price.
The coil cost me 37.

 

I am going to pick it up this morning from Autozone.
though My Father-in-law (previous owner) thinks it has something to do with the smog system, as it seems to die when it is warmed up.

 

The coil is grounded in TWO places. The low voltage (12 volt) side grounds thru the sensor and the high voltage side grounds thru the spark plug. But if you are checking voltage with the sensor on the negative side of the coil you will get all sorts of strange readings. But your symptom of starting and running until warm and then dying is a classic bad coil problem.

 

Success!!!!
Put a new control module in and 20 starts later it is 100%
The replacement took less than 5 minutes.
I'm going to the beach now.
Thanks for the advice.

Bear- What do you have in 45/70? I have been looking at the Marlin 1895 Cowboy

 

Asking me about 45/70 is a no-no. It is my favorite caliber and I have;

A Marlin 1895SS,


Ruger #1,


H&R Buffalo Classic with vintage scope,


H&R Model 1873 "Trapdoor" replica,


My original Model 1873 "Trapdoor" made in 1889,


And of course my Thompson Contender Super 14 shown here with the 1895 and the #1.

 

Thanks for the info.
The local autozone has one in stock waiting for me.
After 23 years, I think its time to change it before it dies
in the middle of no where.

What beach are you going to?
I spend time a Docweiler every year.(its close to home)

Happy trails.
Bruce