[Healeys] Pertronix wiring

[Bob Spidell]

re: "... I don't think a connection between the coil and chassies is a 
good idea ..."

Not only is it a good idea, it is required for a Pertronix 
installation.  A points system grounds the coil to the 
chassis--indirectly--through the points, the 'little “boot lace” wire,' 
the distributor body and the engine.   To use the ubiquitous water 
analogy, the points are 'downstream' of the coil, and the grounding is 
necessary to allow current to flow through the primary winding of the 
coil when the points are closed.  A Pertronix switches current 
'upstream' of the coil; so the coil has to be grounded with a separate 
wire which passes current to ground (the chassis).

In a points system, the coil is 'permanently' grounded by our friend the 
Trusty Cutoff Switch in the boot when the switch is in the 'OFF' (don't 
run) position.   You can retain this 'anti-theft feature' with a 
Pertronix by using the wire from the coil to the cutoff switch--white 
with black trace IIRC--and re-wiring the switch so that the coil is NOT 
grounded when the switch is in the 'OFF' position.   This will prevent 
current flow through the coil regardless of whether the Pertronix is in 
the on or off state. This only requires knowledge of which terminal is 
which on the switch, and a couple of the terminals on the wiring have to 
be replaced since the terminals on the switch are different sizes. Note 
you have to move the wire on the coil as well (which should instigate 
the '+/-' vs. 'SW/BAT(?)' coil markings discussion ;)

As for the 'boot lace' wire inside the distributor, in theory it MAY not 
be needed, as the Pertronix is, in effect, a SPST (single-pole, 
single-throw) switch, and the unit is solid state (duh--that's why we 
like them), but the transistors etc. in the Pertronix probably need a 
ground reference provided through the base of the unit.  I'd leave it in.

Cheers,

Bob


On 12/20/2016 6:39 AM, Per Schoerner wrote:
> Simon
> I have ordered two positive ignitors, one for me and one for a friend. 
> So if you wait a couple of weeks I can probably give you an answer. 
> However, I don't think a connection between the coil and chassies is a 
> good idea, unless the other terminal on the coil is connected to 
> somewhere that is NOT connected to the battery directly. Normally you 
> know, one terminal is connected to the ignition key and the other is 
> connected to the points.
>
> Per
>

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