1956 Pertronix Install

paul5456
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Joined
Dec 12, 2020
Thunderbird Year
1956
56 Tbird - I am installing a Pertronix II with the Pertronix II coil - no resistor. While the instructions are okay, one thing bothers me. The main harness has two wires that go to the factory coil and resistor - a brown wire and a red wire. The instructions only show one wire going to the coil (besides the distributor wire) .
The question is - are both wires ( red and brown) connected to the + side of the coil ? I had the same setup on the car a number of years ago but had to take it off for reasons unrelated to the Pertronix and it seems to me that at the time I only ran the red wire to the coil. Others have told me that both go to the + side of the coil. Can anyone straighten me out ? Thanks
 
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56 Tbird - I am installing a Pertronix II with the Pertronix II coil - no resistor. While the instructions are okay, one thing bothers me. The main harness has two wires that go to the factory coil and resistor - a brown wire and a red wire. The instructions only show one wire going to the coil (besides the distributor wire) .
The question is - are both wires ( red and brown) connected to the + side of the coil ? I had the same setup on the car a number of years ago but had to take it off for reasons unrelated to the Pertronix and it seems to me that at the time I only ran the red wire to the coil. Others have told me that both go to the + side of the coil. Can anyone straighten me out ? Thanks
I don't have any install instructions handy but in the original set up there were two wires that went to the coil because there was one wire that ran from the ignition switch and then to the resistor and then to the coil. That was the wire that supplied the power when the car was running. Technically it also supplied power while the car was being started but when the car was being started that second wire came from the starter solenoid and supplied full power, bypassing the resistor, while the solenoid was turned on to crank the engine. I think it connected to the I terminal on the solenoid and I believe it was yellow and/or brown, maybe one was a stripe. The one from the resistor looks like it was black. If the one you saw was red it might be that the black wire (from the resistor that isn't used with the petronix, was simply set aside and a red one used. Who knows how someone might have done the wiring years ago. Everything I"ve seen says get rid of the resistor in the circuit because you need to get the full 12 volts to the Petronix. But I've also seen posts saying some coils can't handle the full 12 volts so you need to still use it in the feed to the coil but not in the feed wire to the petronix. I think that gets people tripped up. You can also buy coils that are designed to work properly with the full 12 volts.
 
I don't have any install instructions handy but in the original set up there were two wires that went to the coil because there was one wire that ran from the ignition switch and then to the resistor and then to the coil. That was the wire that supplied the power when the car was running. Technically it also supplied power while the car was being started but when the car was being started that second wire came from the starter solenoid and supplied full power, bypassing the resistor, while the solenoid was turned on to crank the engine. I think it connected to the I terminal on the solenoid and I believe it was yellow and/or brown, maybe one was a stripe. The one from the resistor looks like it was black. If the one you saw was red it might be that the black wire (from the resistor that isn't used with the petronix, was simply set aside and a red one used. Who knows how someone might have done the wiring years ago. Everything I"ve seen says get rid of the resistor in the circuit because you need to get the full 12 volts to the Petronix. But I've also seen posts saying some coils can't handle the full 12 volts so you need to still use it in the feed to the coil but not in the feed wire to the petronix. I think that gets people tripped up. You can also buy coils that are designed to work properly with the full 12 volts.
The red wire goes to the resistor bottom and at the top of the resistor is the black wire that goes to the + side of the coil. That should be the run power to save the points/coil. The brown wire goes directly to the + side of the coil, so that must be the start power.

Thanks for your help.
 
56 Tbird - I am installing a Pertronix II with the Pertronix II coil - no resistor. While the instructions are okay, one thing bothers me. The main harness has two wires that go to the factory coil and resistor - a brown wire and a red wire. The instructions only show one wire going to the coil (besides the distributor wire) .
The question is - are both wires ( red and brown) connected to the + side of the coil ? I had the same setup on the car a number of years ago but had to take it off for reasons unrelated to the Pertronix and it seems to me that at the time I only ran the red wire to the coil. Others have told me that both go to the + side of the coil. Can anyone straighten me out ? Thanks
see: https://forums.fordthunderbirdforum.com/threads/1955-pertronix-positive-ground-wiring-fyi.14046/
 
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