[TR] Ignition question; not really TR, but could be!

Randall TR3driver at ca.rr.com
Sat Apr 9 01:42:49 MDT 2011


> We've 
> tested the coil on the 
> car and  it reads 1.5 ohms.

That would be a very typical value for an "external ballast required" coil,
which is what most cars after 1970 or so used (until the advent of HEI,
etc).  The car will have some sort of resistance (likely resistor wire in
the harness, but some use a discrete resistor mounted somewhere) that limits
current through the coil.  The advantage of doing it that way is that the
starter circuit can short out the resistor, giving a hotter spark when the
battery voltage is being sapped by starting the car, and making it easier to
start with the various smog equipment.

To use the original coil, you need to keep that resistance in series with
the coil, while finding a full 12v to supply to the Pertronix.  The
information on how to wire with a ballast resistor used to be in the
Pertronix instructions.  If not, let me know and I'll send you a PDF.

-- Randall  



More information about the Triumphs mailing list