healeys
[Top] [All Lists]

Re: Coil

To: "Patton Dickson" <57healey@gmail.com>,
Subject: Re: Coil
From: "Bob Spidell" <bspidell@comcast.net>
Date: Sat, 21 May 2005 09:15:00 -0700
re:

" I think that means the polarity of the car would be what is coming from
 the switch, and the oppisite out to the distrubutor. "


Believe that's backwards.  "Positive ground" means current from SW is
(relatively) negative, and vice versa.


CB=Contact Breaker=points

Points switch the circuit to ground (electronic ignitions; e.g. Pertronix, 
switch the 
current "upstream" of the coil, whose CB terminal is always grounded).

Since Mel's car is negative ground, the "-" terminal of the coil should go to 
the
distributor/points.  I think the "SW/CB" labeled coils assume positive
ground, so if you switched polarity to neg. ground and left the CB terminal 
connected
to the dist. the coil polarity would be wrong ... the engine would still run, 
but a little
less efficiently.

I suspect the coil manufacturers went to "+/-" labels due to the large number 
of 
conversions to neg. ground.

Think Norm Nock has a good writeup of this in his Tech Book ;)


bs

***************************************************************
Bob Spidell         San Jose, CA        bspidell@comcast.net
'67 Austin-Healey 3000             '56 Austin-Healey 100M
***************************************************************
Subject: Re: Coil


> If I remember right SW = Switch side and CB = Contact Breaker side.  I
> think that means the polarity of the car would be what is coming from
> the switch, and the oppisite out to the distrubutor.   So on a
> negative ground car SW=Negative and CB=Positive.
> 
> Someone please veryify, but I wanted to make sure my logic is right.
> 
> Patton
> 
> On 5/21/05, Mel  Brunet <mburnet@tampabay.rr.com> wrote:
>> Enthusiasts
>> 
>> I just purchased a new coil for my 67 BJ8 negative ground car from AH Spares
>>  The new coil is marked  + and - instead of SW and CB.  Can someone tell me
>> if CB is + or - ?
>> 
>> TIA
>> 
>> Mel Brunet
>> 67 39749
> 
> -- 
> Patton Dickson - Richmond, TX
> '57 A-H 100-Six - http://Austin-Healeys.com




<Prev in Thread] Current Thread [Next in Thread>