Resistance wire removal or replacement.
If installing an electronic ignition system the resistance wire most likely has to be removed or bypassed. There are several ways to do this and the solution depends if you have the 1963/64 4-speed Hydra-Matic transmission or the 1964 3-speed Turbo Hydra-Matic transmission. There is also a Ignition Power Relay supplied by PerTronix but that will not be discussed in this thread.
If your car is equipped with the 3-speed Turbo Hydra-Matic the easiest way is to remove the resistance wire from the coil and secure it or remove it completely. After that take a new fresh wire and connect it to the switch on the transmission downshift. The pink wire going from the ignition switch on the dash to the switch, is the same wire the resistance wire is connected too. So just connect to that pink wire and you are home-free.
If your car has the 4-speed Hydra-Matic life is a bit more tricky. So now its time for some pictures and explanations.
1. The red arrow is pointing to the brownish resistance wire. It is normally taped together with the yellow wire (starter solenoid) and the green wire (temp gauge). 2. At the yellow circle the wires will go three ways and you have to open this up. 3. The blue circle is showing the wires going through bulk-head into the cock-pit.
Here is the device on the bulk-head partly removed.
Here is all opened up and as suggested by Jason Edge you should be able to carefully pull out the resistance wire and free it from the pink ignition wire. (Red arrow is pointing to the resistance wire)
However on my car it was not possible to pull trough the hole in the bulk-head and I had to do the job inside the instrument panel. To facilitate the job I removed the dash and the steering column lower cover. Found the connection between the two pink wires and the brownish resistance wire.
Removed the tape. (Hard to focus with the phone camera)
Connected the two pink wires (the ignition switch and the fuse box) with the new wire to the ignition coil. If you have a Turbo Hydra-Matic you will have three pink wires here instead of two, as the third wire is going to the transmission downshift switch.
When this job is done you have to secure it all again and pay attention to protection of the wires.
Here the new red wire is connected to the plus on the new ignition coil together with the yellow wire from the starter solenoid and the wire from the electronic ignition. The green arrow is for the green wire to the temperature gauge.
After this new rotor, distributor cap, spark plug wires and spark plugs. Remember that you might have to increase the gap size on the spark plugs as you now will have a hotter and cleaner spark. Depending on plugs used you might have to increase distance to 0,035-0,040".
When all is set and done. Start your car. Run it until normal working temperature and do a complete ignition timing adjustment as per 1964 Cadillac Shop Manual page 12-17 to 12-18 (I don't have a 1963 Shop manual so don't know the pages in that book).
I tapped in at the kickdown switch. You can go to pink "ignition wire behind dash (which feeds the kick down pink wire), or go all the way back to the fuse box. For 1964 Cadillac owners with the Turbo Hydramatic and the kickdown switch, that is the easist "switched 12 volt source".