>QUESTION :
>Does anybody know hoe the ballast resistor is wired in ignition
>circuit of a late Midget ?
>I have looked at several wiring diagrams and none show a ballast resistor.
>The coil says to use one and the Allison Elec ign instructions
>say "NEVER RUN WITHOUT A BALLAST RESISTOR" - yet I can not find
>a wiring diagram anywhere !!!!!
Well, I can't speak from experience about a Midget, but I have run into this
installing a Lumenition ignition on both my TR-8 and a friends Lancia
Scorpion. (The
Lancia has convinced me that there are worse things in this world than Lucas
electronics.) Most post 1960 cars (which may not include a Midget) use an ~8
volt ignition system, and shunt 12 volts to the coil only when starting. The
purpose
of the ballast resistor is to drop the voltage from twelve to eight volts. If
the
Allison ignition is similar to the Lumenition one, it needs twelve volts to run
on,
but is designed to drive an eight volt coil. (It also sounds like your coil is
designed for eight volts - thus the warning sticker.) There is a way to
determine
whether your current coil is designed for eight or twelve volts by measuring its
resistance, but I'm afraid I can't remember what range to expect for each coil
type.
Maybe someone else can help out.
Here is my version of your diagram. Note the change in where the ignition gets
it power.
-------- Black
|Elec |----------------------------------------------|
|Ign | |
| | Red |-------------------| |
| |-------------| ballast resistor |--| |
-------- ^ |-------------------| | |
| | |+ve | -ve
| | ---------------
| | | |
| | | |
Earth 12 Volts | |
| Coil |
| |
| |
| |
---------------
Does your Midget have a ballast resistor? If not, you may have trouble
converting to
the Allison unit.
-Barry Klawans
barry@sybase.com
|