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).

Good luck

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Nice write-up! I have added to our Help page.

Wonderful write up with pictures and arrows to boot !
Like your computer skills and this tread is a nice addition to the site with many using the Pertronics Ignitions
Input like this allows the DIY guys to have a heads up at doing the task
Nice work from Sweden branch


Hey, guys, it's been awhile, I've been super busy with life in general so it's tough to think about my caddy when so many other things are going on right now. I hope everyone had a happy new year!

I saw this thread and it caught my attention. Just to make sure, if one has the 3 speed Turbo Hydra-Matic, you splice a new 12 gauge wire into the trans kick down switch PINK wire, and route it back to the positive side of the coil?

If so, then I did this correctly in my 64. But sometimes I feel like I lost a bit of power from a dead stop compared to when I had the Ignitor II setup when the Caddy felt like a rocket ship on take off!!

Might have to re-gap the plugs from .35 to .40 and see if that makes a difference as everything else was the same prior to upgrading the Ignitor III setup. New plugs, wires, cap, and rotor so those are not of concern.

Chris, both the Pertronix Ignitor ignition system (I,II or III), and the Flamethrower Coils are designed for a full 12 volts. For those of us with the 1964 body styles with the Turbo Hydramatic transmission, we can:
1. --> use the pink switched "ignition" wire that feeds the transmission kick-down switch.
2. --> Another choice would be to follow the resistor wire to behind the firewall to its connection with the pink wire and tap into the same pink wire circuit before it splits to the kick-down switch.
3. --> wire direct to the switched accessory post on the fuse box.
==> For 1963 owners, and 1964 with the Hydramatic, #1 is not an option leaving 2 and 3.

Sounds like you have yours set up correctly. I think I have my spark plug gap set at .042. I would also suggest checking the timing and carb set-up on your car. Adjusting the timing slightly 1 degree advance might provide a big improvement. Also make sure distributor advance, plug wires, etc are all up to snuff!

Hey Jason, yeah my plugs, wires and distributor advance is all newish and timing is about 8 degrees BTC . So I did do it right then. Since I installed the petronix III setup last year, I never did re-adjusted the gap on the spark plugs to a larger gap. I kept them at .035. I’m going to pull them all out and set them at .045 and see if there’s an improvement.

Also I would like to mention, the brand of spark plugs make a HUGE difference in terms of how these engines perform and idle. Stay away from AC Delco, and Champions as they will make your engine run like crap. I found that the stock Autolites run great, as well as the NGKs that honestly run even smoother than the Autolites.

I run AutoLite 85's in my 64 CDV and works perfect. I use to run the expensive Bosh Platinum 4236 but decided to try some of the standard plugs and AutoLites worked perfect for me and are very cheap. I probably keep about 4 sets on the shelf at all times. On the gap, I would run it at 45 for a week (or at least under different city/driving conditions), then go back to 40. and run for a week and adjust up or down from there.  45 is about a 29% increase in gap size so you might end up like me pulling it back in a bit. 42 just seemed to feel best for my car but each one will be different.

Thanks Jay for the tips. I guess I’ll try that out and see how the engine feels. Im also currently running the 85 Autolites for stock reasons, but I think I’ll put the NGKs back in with a higher gap and test the engine out with those plugs since the caddy ran the best with the NGKs.

Using the Autolight 85 plug for over 45 years In my 64 -429
It is the same heat range as the stock AC delco plug
Developed my --love for the brand --when they were the plug that held up about twice as good as other brands in my Super Stock drag race track car


The NGK pugs have a broader heat range than many other plugs
I have used them on other cars and like that brand as well


Chris I too had a loss of power switching to petronix 2 . I changed from old worn out points to boot. I had done a baseline timing before the change and it was at 10 or 12 degrees. I can't remember now for sure. I also had new plugs, wires and vacuum advance previously installed. When i ran the timing at 5 degrees I had a slight hesitation or bog when I mashed it at 5-10 mph or so. I ended up at 8 degrees and was happy there. I still don't feel I've got any performance improvements but with the touch of a key it will fire right up. This spring I'm going to move back to 10 degrees timing to try that with the fuel injection I've also installed. Make sure you have ported vacuum to your vacuum advance not manifold vacuum.  With ported there should be no vacuum at the advance when idling. As the carburetor butterflies open a small port is slowly subgected to engine vacuum. This is the correct factory set up.

Clovis, strange how you had the same problem with loss of power going from points to a pertronix setup. I had a slight bog and performance hit going from the ignitor II with the old flamethrower II coil, to the ignitor III+ flamethrower III coil even after playing with the timing, I still feel like the engine has a little less power now than before for whatever reasons. This is why i suspect that if I increase the plug gap, I could gain some of the power back as well as reinstalling the NGK plugs I had in before which the engine loved. As for the vac advance, it’s ported vacuum going to the advance as there’s no vacuum being sucked from the hose at idle, only when the engine is revved like how it’s supposed to.

If your timing was set higher with the point set up than the Pertronics install ( as Clovis said his was at 10-12 degrees )
Timing advance is a major source of additional power as long as the engine does not ping ( cause detonation ) with the fuel octane avaiable
Higher timing will cause more --low end torque --to happen making the car feel --a bit -more responsive
I know both Clovis and i run 8 degrees advance on the crank
If you do not have --your foot in the carb all the time --you --may be able --to run 10 degrees advance on 92-93 octane
If your timing has been reduced due to the Pertronics install that would explain a feelin of reduced power to me

Jason is at 5 degrees per the book and has no interest in any changes there
He suggests that something is wrong elsewhere if you need to be over 5
I would love for him to go to 8 -- or more as he runs higher octane gas somtimes --and report back
I ran 12 degrees in my 62 Cadillac 390 when the fuel allowed that to happen -- back in the day ( i just love to saying that )
It just takes a few minutes to try the change
I would think Jason would see more of a performance increase due to his carb and cam upgrade
Advanced timing inproves gas mileage and reduces engine temps some
I did a lot of work with timing in my Drag race days on the track

My total advance on my big block chevy was 38 degrees ( the engine can blow at 40 )
And the dist advance curve was changed to be fully advanced at 2000 RPMs ( done on a sun dist machine --which is no longer done by anyone today --i checked )
I did want to have my 64 dist checked on a sun machine but no one is using that machine today




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