Hi Steve,
The Flamethrower II coil has a primary (low-voltage) resistance of 0.6 ohms.
That means if you connect it directly across 12V and ground, it will pull 20
amps and dissipate 240 watts. This causes the coil to get HOT in a hurry,
and if you leave it like that even for a few minutes then it will severely
reduce the life of the coil, if not fry the thing altogether. I was recently
using a Flamethrower II in my tach testing setup, with a Mallory Unilite
distributor. The Unilite doesn't have any protection to turn off the coil
current when the distributor isn't turning, and leaving the system energized
would overheat the coil in a matter of minutes.
If you want to test the system like that, then grab a couple of spare
headlights and wire them in place of the coil, then go looking for the
source of your voltage drop.
The Pertronix module depends on the internal grounding of the distributor's
advance plate. You should make sure that the mounting surfaces inside your
distributor and under the distributor's mounting flange to the block are
clean, and that you have a good ground between the engine and chassis. For
distributors with a movable breaker plate (not like your dual-point unit) it
is essential that the little ground strap wire inside the distributor be
connected between the breaker plate and the distributor body.
Good luck,
Theo
-----Original Message-----
I spoke to Pertronix again today and got a knowledgeable (I think) support
tech. He thinks my voltage is too low at the coil. With the car running, I
get 13+ volts at the coil output terminal (that leads to the ignition module
inside the distributor cap). With the engine off but the ignition switch on,
following the tech's instructions, I ran a ground wire from the negative
coil terminal to a ground on the motor. In this mode I get a bit over 7
volts at the positive coil terminal. The Pertronix tech says this is too
low, and that in this mode (engine off, ignition on) I should be getting at
least 9 volts, and ideally I should be getting a full 12 volts. He said
what's probably happening is that when the car and the wiring heats up,
there's even more resistance, and less voltage gets to the module. He said
that when voltage goes below what it needs, it would behave just like I'm
describing. He says I've got resistance somewhere between the ignition
switch and the coil, preventing the needed juice from getting to the coil.
So, how do I solve the problem and get at least 9, and hopefully up to
12 volts at the coil, with the engine off?
Steve Sage
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