The ballast resistor reduces the amount of current flowing through the
points and coil. Advantages include less pitting of the points and cooler
coil operation. If you check the voltage drop across the coil when the
points are closed, you will get a reading of about 6 volts, which means the
other six is being dropped across the ballast resistor. In some cars, the
resistor is a special wire, in others, it's a ceramic rectangle that has
connections on each end for supply (ignition) and coil. You can buy this
type of resistor at most auto parts stores. Most ignition systems with
ballast resistors have a system for bypassing the resistor when the starter
motor is cranking, providing 12 V to the coil to start.
Mark Anderton
72 TR6
Virginia Beach
http://members.cox.net/andertonm/car_stuff.html
----- Original Message -----
From: "TR6 Triumph" <tr6_1969@hotmail.com>
To: <6pack@autox.team.net>
Sent: Monday, June 30, 2003 3:54 PM
Subject: Ballast resistor question
> Hi list!
>
> The posting speaking about the bad points possibly caused by lack of a
> ballast resistor forces me to ask the questions: what is a ballast
resistor
> and what exactly does it do in the ignition circuitry. Further, why do
some
> systems have them and others do not? On the TR6 was it the earlier ones
> that didn't have them but the later ones did? What does the ballast
> resistor look like and where is it? Thank you.
>
> Sincerely,
> Dave Herbert
> 1969 TR6 and nothing else
>
> _________________________________________________________________
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