Gerry,
Your ballast resistor picture is not quite correct. It would typically be in
series in the primary circuit. Since most systems have a feature to bypass the
resistor during starting, they would typically look like:
key resistor + -
+12 o--->|-----o\/\/\/\/o------o o--------o--->|-----(earth)
| | .!----!. points
| | | | in
o--->|--------------- |______| distributor
| starter coil
| position
---->|----------------->to starter solenoid
The idea is to limit the current in the coil during normal running, but not
during starting.
An electronic ignition module is just an ordinary electronic device that
wants to have its full allotment of voltage, so you want to feed it an
"unobstructed" 12 volts. Whether you still want to protect the coil with
a ballast resistor is another story, probably depending on the coil. If
the Allison system includes a coil and it still says no resistor, then
don't use one at all. Otherwise your picture should be ammended to be:
-------- Black
|Elec |-------------------------------|
|Ign | Red |
| |------ |
-------- | |
| | |------>--|+ve | -ve
| | | ---------------
| | ---- | |
Earth | | | | |
| | | | Coil |
| | | | |
| | | ---------------
| | |
| ---- <--ballast resistor
| ^
| |
-----o
|
12Volts
The same starter switch arrangement should also be provided to bypass the
resistor, giving full voltage to the coil during starting.
Perhaps (probably!) someone will give particulars for that year Midget, but
this is how a ballast resistor would typically apply to a normal distributor.
I am guessing at how the electronic ignition module wants to work, but this
makes sense, especially with your quote from Allison. It is quite possible
that there should be none at all, even wired coil-only. But you certainly
don't want the resistor in the 12 volt line feeding the E.I. module.
Jim
|