39 No fire at the plugs

1939Deluxesedan

1939Deluxesedan

Member
I'm trying to start this car after decades of sitting up. It has a Mallory distributor with a new coil. I have it configured for 12 volt, negative ground. Only the ignition and starter are active, at this point. So if I apply +12 to the coil+, and negative to the - of the coil, it should produce a spark at the plugs when it spins over? Right? What am I missing? I had to install new plug wires and had to crimp the ends. something I have never done before. Each ohm out at 100-150 ohms. A good reading since there is 50 ohms of loss per foot. I checked for spark of the coil. Its not there. I've looked at some you tube videos for the Mallory crab type distributor. It seems pretty fool proof, but what good is that if it won't produce a spark?
I'm thinking the Mallory is trash. What is a better ignition in 2021? One with tech support, and a place to get questions answered?
Thanks.
 
The negative post on the coil, on a 12v neg ground system, should be connected to the points in the distributor. The points may be dirty and not making contact. You might try cleaning them with a point file.
 
I don't think it has points.

One more question. What is the resister for? I always thought for dropping the 12v back to 6, for the other accessories. That's just a guess. Does it need to be in series with the coil+?
 
You have an electronic Mallory distributor. The red lead from the distributor goes to + on the coil,green goes to - and brown goes to ground. The battery connects to + on the coil. This is for a negative ground system. No resistor needed with the coil you have. Do not leave the hot lead connected to the coil for an extended time with the car not running.
 
There's always the possibility that the electronic ignition module is bad. They are not known for their reliability, and sitting for long periods in non-optimal storage conditions is not good for them. If it was a conventional system, I would put a meter between the coil and the distributor and see if it makes and breaks. I would think that an electronic unit could be checked that way as well.

And in my opinion, "a better ignition in 2021" is a properly set up stock crab (with points) and "a place to get questions answered" is right here. I will guarantee it is better by a long shot than tech support at some big company where their flathead products are not the current "hot ticket".
 
tubman said:
There's always the possibility that the electronic ignition module is bad. They are not known for their reliability, and sitting for long periods in non-optimal storage conditions is not good for them. If it was a conventional system, I would put a meter between the coil and the distributor and see if it makes and breaks. I would think that an electronic unit could be checked that way as well.

And in my opinion, "a better ignition in 2021" is a properly set up stock crab (with points) and "a place to get questions answered" is right here. I will guarantee it is better by a long shot than tech support at some big company where their flathead products are not the current "hot ticket".
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That's what I am thinking as well. I never saw it produce a spark. What I see offered for sale now looks like the one that is on the car now. The one that failed. The exception is the cheaper "speedmaster". The video I saw of the setup for the duel points Mallory looks a little intimidating. What is the reason for your preference for the points system over the straight solid state unit? can the addition of not one, but 2 mechanical points (duel) help with reliability? Just asking.
 
You sent that distributor to me and it worked perfectly here. I have had the exact same distributor on my 39 for 25 years
 
First, I don't know squat about a Mallory distributor. But the negative side of the coil goes to the distributor in a negative ground system. The original post said the coil was wired with battery negative to coil negative. If you put a battery negative on the coil, the distributor is grounded and can't produce spark.
 
It should be wired just like I said in post 6. As I said, I have this exact same distributor on my engine for 25 years so I think that qualifies me as knowing how it should be done. Period.
 
You can never be sure of anything. The module may have failed spontaneously after Jack had it, or more likely, it may nave been dropped or suffered other damage in transit. The only thing is to somehow test it and make sure it is functioning properly. Unfortunately, I am not into electronic ignitions and have no idea how to do it or even if it can be done.
 
It is explained a little strange in the original post as far as how the distributor and coil is wired. It may just be a typo, but as written, it would not work. Flatjack9 provided the correct wiring.
 
flatjack9 said:
You have an electronic Mallory distributor. The red lead from the distributor goes to + on the coil,green goes to - and brown goes to ground. The battery connects to + on the coil. This is for a negative ground system. No resistor needed with the coil you have. Do not leave the hot lead connected to the coil for an extended time with the car not running.
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The positive 12 volts goes to the + side of the coil. Negative to the negative on the coil. Green to chassis ground from the harness. On the battery, + goes to the starter solenoid. Negative on the battery goes to lug on the engine providing chassis ground. All these connections have been verified multiple times with a VOM for continuity and voltage.
I guess it is possible something could have come loose in transit.
Does the coil require some odd voltage? Is this the reason for the resistor?
All I know is it won't produce a spark, regardless of the configuration. Pretty frustrating. Sometimes it just best to walk away from it for awhile. Let it sit.
 
Ok, what does this mean "The positive 12 volts goes to the + side of the coil. Negative to the negative on the coil." Negative what? You need to keep in mind that this is most likely clear to you, but it is very confusing to me. A negative is the same as a ground, so it could be read as a ground being connected to the (-) side of the coil. What negative are you referring to, the Green wire on the distributor?
 
1939Deluxesedan said:
The positive 12 volts goes to the + side of the coil. Negative to the negative on the coil. Green to chassis ground from the harness. On the battery, + goes to the starter solenoid. Negative on the battery goes to lug on the engine providing chassis ground. All these connections have been verified multiple times with a VOM for continuity and voltage.
I guess it is possible something could have come loose in transit.
Does the coil require some odd voltage? Is this the reason for the resistor?
All I know is it won't produce a spark, regardless of the configuration. Pretty frustrating. Sometimes it just best to walk away from it for awhile. Let it sit.
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Read post #6. I don't know how I can be any clearer. NO RESISTOR. You are wiring it wrong!!!!!!!!
 
JSeery said:
Ok, what does this mean "The positive 12 volts goes to the + side of the coil. Negative to the negative on the coil." Negative what? You need to keep in mind that this is most likely clear to you, but it is very confusing to me. A negative is the same as a ground, so it could be read as a ground being connected to the (-) side of the coil. What negative are you referring to, the Green wire on the distributor?
Click to expand...

As I said, green from the distributor goes to - on the coil, red from the distributor goes to + on the coil, brown from the distributor goes to ground. Hot lead from the battery goes to + on the coil. Voila - spark.
 
I know, agree, but doesn't sound like how he has it wired. He keeps referring to a negative to the (-) side of the coil. But no idea what he is considering a negative.
 
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