> When I turn the ignition on I an getting 12V at the coil ( the coil has
> three small lead attached to it - a yellow one from the harness and the red
> and black leads from the ignitor) The yellow and red leads are attached to
> + terminals on the coil and the black is attached to - lead. Does anyone
> have any idea why I wouldn't be getting spark at the coil?
I agree with Ed, most likely (IMO) explanation is that the Pertronix module has
failed. Might be the wires or coil, but they're pretty reliable.
> Also, I keep
> hearing about resistor on coils - just where is this resistor located?
On a 73 TR6, I believe it's a special resistor wire, incorporated inside the
harness. I believe the insulation should be slate with a white tracer. I'm not
sure why your wire is yellow. Probably the easiest way to find out if the
resistance is present is to temporarily jumper the other side of the coil to
ground and turn on the key. If the resistance is present (and the coil is
good), the voltage at the hot wire to the coil should drop to 6-9 volts.
If someone has eliminated the resistor, it may explain your Pertronix failure
... with a Pertronix, if the coil is designed for a resistor, then a resistor
must be present. The 'proper' coil is designed for a resistor, so if you used
it without one, the current would be too high and perhaps shorten the life of
the Pertronix module.
OTOH, I believe Pertronix suggests that the red wire be connected to the
ignition switch side of the resistor (if a resistor is present), so that could
be a problem, too.
> Any
> advice on how I go about debugging this is much appreciated!
My next step would be to connect an incandescent test lamp across the low
tension terminals of the coil and crank the engine. You should be able to see
the lamp flash rapidly (or glow dimly) as the engine cranks. If the lamp
doesn't come on, or stays on full bright, then the Ignitor is not working.
Next step is a careful inspection of all the wires to the Ignitor, especially
where they enter the distributor housing. I'm not certain offhand, but I
suspect that it needs a ground through the point plate too, so use your
voltmeter to be sure it's getting ground. Also check that the gap is
reasonable, and that the distributor shaft turns when you crank the engine.
(Don't laugh, it's happened to me, although not on a Triumph.) And that the
magnet assembly is in good shape.
If none of that turns up a problem, IMO it's new module (or back to points)
time.
Randall
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