1957 no spark to coil

twstnshout

twstnshout

Active Member
Last seen
Joined
Nov 19, 2021
Thunderbird Year
1957
Tried everything can’t get power to coil. The 312 was totally rebuilt I saw motor running great on a stand. There is continuity through brown and red leads from new ignition switch. Installed new Petronius distributor and high voltage coil at rebuild.
 

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Tried everything can’t get power to coil. The 312 was totally rebuilt I saw motor running great on a stand. There is continuity through brown and red leads from new ignition switch. Installed new Petronius distributor and high voltage coil at rebuild.
Did you bypass the original ballast resistor? With the Peertronix that is suggested and is correct to get full voltage to the module. Do you have any voltage at all going from the ignition switch to the coil?
 
I did By pass the resistor left it there for decoration. When I crank with test light across poles there is no indication of voltage reaching coil
 
Have you checked for power at the “S” terminal of the new ignition switch, or checked continuity through it?
Is it an NOS switch
 
I have checked continuity on both brown and red leads. The engine cranks so the S post is getting voltage and energizing the starter relay. It’s a brand new ignition switch that doesn’t seem to be sending voltage out of the ign post.
 
Recheck the wires at the ignition switch, there should be two wires on terminal “C”
One goes to the coil and the other goes to the gen and oil pressure lights.
If they are both there then check with the key in run position that the lights are on
 
The C post connection is a single ganged O ring connection with the 3 wires still. I don’t have lights or horn connected yet. Do their power come of ignition switch? I do have power to the ACC post I do get a reading on the fuel gage and the heater blower runs when the key is in “on” position. If I turn key to on”position would a volt meter show a reading?
 
When I connect battery, & turn key on my volt meter reads 12 volts on the starter relay and 12 volts on the + and - poles on my coil. There is no spark when I air gap my coil to distributor wire to ground.
 
Power to the coil comes from the “C” terminal of the ignition switch, do you have power there?
 
12.85 volts to the C post when key is in on postion
 
Sometimes you just have virtually start over. Trace the changes you made and any dletions from the original wiring.
 
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