It’s too bad I hadn’t taken some pictures of the wave pattern on the scope, but it’s a distorted sine wave with the the steepest slope at alignment and the shallowest between alignment. Reversing the wires simply flips the pattern. The real question is which zero-crossing direction change triggers your amplifier.

One way to tell is to test the system on the bench by connecting the uninstalled distributor to the amplifier and coil, and then to a battery. Insert a wire in the coil and within 1/4” of ground, and then twist the distributor shaft by hand and see the alignment when spark occurs. If you attach a timing light to the coil and turn the distributor with a drill (or distributor machine), the flashing will show exactly where triggering occurs. If it’s not at alignment, the wires are reversed..

 

Here are my notes on the Pickup Coil wiring configuration along with some additional information for future reference........ Rich

=======================================

Distributor Pickup Coil wiring:

Dist Conn <------> TI Harness Conn
-----------------------------------------------
White <------> Pink (Double wire) - one from IGN, other from Solenoid R terminal (Full Bat+ at START/Crank).. See *** below.

White/Green(Solid Green on Service replacements) <-------> Gray.(TI Module trigger Input)

*** This yields full Bat+ to both distributor PU Coil input and TI Circuit Module electronics. TI requires highest battery voltage possible during crank) If not, you may get ONE and only ONE spark while keying back from START to RUN. By design, TI will always yield ONE spark at either key ON...... or key OFF. Any TI fault could react with this effect.


From CSM with my notes:


TI System Circuit and Harness Notes:

TI Harness uses 2 White braided resistor wires(R7,R8).

R7 is the main power feed resistor wire from IGN switch and should measure approximately 0.7 ohms.(static. open circuit end to end)

R8 is the TI module pulsed output to IGN Coil+ and should measure approximately 0.3 ohms..(static. open circuit end to end)

Note that with IGN ON(not running) you should read apx 2.5 to 4.5V at coil+(66-71 TI) or apx 5.0 to 7V at coil+(64-65 TI) , which is the output of TR1 final power transistor stage. This varies between 64-65 TI and 66+ TI because the harness resistor wiring to Coil + and Coil - uses 2 different configurations. See CSM Wiring Diagrams and CSM Diagnosis Charts below.

With a Points Ignition system you will read ~9v to ~12.6v(~9v= points closed, 12.6v points open, fully charged battery). Completely different on a TI System as you're reading a transistor DC output through a resistor wire not a Ballast resistor raw voltage as in a points system.

Here is a photo of the Distributor PU Coil connector mated with the TI Harness Connector. Note this is a Service replacement PU Coil.(Solid Green vs original White/Green)


Here is the Distributor connector terminal configuration: A way to remember configuration..... White at the plastic housing lock tab terminal.




CSM Wiring and CSM Diagnosis Charts(Attached PDFs):

64-65 Note Resistor wire goes to Coil - Also note drawn PU Coil connector configuration and wire color placement on all years.


66-71 (Note Resistor wire goes to Coil + ) Note 18G Yellow wire to Solenoid R as shown is actually solid Pink on 1966/1967. (CSM error)

 

I didn't see any distributor waveform pictures posted, so I dug up an old picture that shows the typical waveform for variable reluctance sensors found in TI, HEI, and other similar distributors. As discussed earlier, the signal voltage steadily increases as the reluctor wheel teeth get closer to the magnet teeth. As the reluctor wheel teeth pass by the magnet teeth the signal polarity quickly reverses. It is the steep negative portion/transition that signals the TI module output transistor to shut off, therby firing the coil.


Just for easier viewing of what happens if the sensor wires are swapped, I flipped the picture (below) to show the waveform that would end up controlling the module. As mentioned before, it is the negative transition of the waveform that tells the module to fire the coil. The obvious thing seen here is that the coil will fire substantially later than when the reluctor teeth align. (The rotor and cap electrodes are in less than ideal positional relationship with each other under these conditions, potentially causing misfire) Another thing that's not quite as obvious is the effect on the coil output voltage. The maximum theoretical voltage that an ignition coil will output depends on how quickly you shut off the primary current. As you can see, the slope of the falling voltage is now comparatively slow. Depending on the gain of the turn-off circuitry (it's been a few years since I examined the TI schematic closely), the slower rate that the primary current gets shut off will reduce the magnitude of the coil (high voltage) secondary output, adding additional misfire susceptibility under higher load conditions.