One point, the Petronix (sp?) that is occasionally mentioned on this site,
has two wires going to it. It still needs the ballisted voltage (black
wire) going through the points, however, the red wire, which powers the unit
itself needs 12 volts, for it quits working at about 4.5 volts. This wire
needs to be run to the front end of the ballast resistor. The problem is
that the resistor basically halves the voltage, and if the voltage drops
below 10 volts, as it may after a hard start, (not saying that the roadsters
are ever hard starting), you are on the hairy edge of the unit dropping out.
I didn't know that they needed different voltaves, and finding out about the
voltage dropout, bypassed the ballast all together - both wires going to the
12 volts......smoked the unit.
From: SPL311RDST@aol.com [mailto:SPL311RDST@aol.com]
Sent: Wednesday, November 01, 2000 1:38 AM
To: firstname.lastname@example.org; email@example.com
Subject: Re: ballast resis. more info
In a message dated 10/31/00 3:01:53 PM US Mountain Standard Time,
> I do believe you are wrong on this one.
I'm not & you're not completely wrong either.
>The ballast resistor is used to cut
> down the voltage when the resistor gets heated up. It reduces the voltage
> the points don't burn,
The resistor gets heated up 'cause it is cutting down the voltage - you got
the cause & effect mixed up here. And yes... it is reducing the 12v down to
7.5 so the points are OK. The full 12v is for starting only. Go make some
toast - i'ts a big reisistor that gets really hot when you put 110v to it !
> hence electronic ignitions don't use resistors.
I'ts not because they don't have points - it's because most are designed to
utilize a full 12v. The typical GM HEI uses 12v. for example. Chrylser
products started putting elect ign in their cars in '72 -they still used an
external ballast resistor in their set-up as it had a lower voltage
requirement, even though points were absent.
> On start up the resistor is bypassed.