In a message dated 98-07-01 21:54:36 EDT, deboer@duke.usask.ca writes:
> The subject line says it all. Am I correct in assuming that the + side on
> the coil should be connected to the distributor whereas the - side gets the
> 12 volt feed? Reason I ask is that the diagrams I have in the Bentley and
> the Haines do not have labels of + and - next to the coil, but instead
> markings of SW and CB, if I remember correctly.
Dirk,
Currently, there are several of us (all electrical engineers) from the Triumph
list involved in a detailed study of this very question. We haven't come up
with quanitative answers yet, but we have come to some conclusions.
1) It dosn't really matter for most applications which way you connect the
coil. We base this on the number of folks we know, and know of through the
list, that have connected the coils wrong, with no obvious problems.
2) reversing the coil polarity when you swap the ground polarity is not
correct, neither is not reversing the coil polarity.
3) The "correct" way to wire the coil is to use a coil designed for positive
ground on a car with positive ground, and a coil designed for negative ground
on a car with a negative ground.
4) if you are using the correct coil, the distributor lead polarity should
match the ground polarity. On a positive ground car, the terminal marked CB
goes to the distributor, and is the positive terminal. The terminal marked SW
goes to the ignition switch, and is the negative terminal.
I have drawn a couple of diagrams, in jpg format, illustrating this, if any
one is interested.
Dan Masters,
Alcoa, TN
'71 TR6---------3000mile/year driver, fully restored
'71 TR6---------undergoing full restoration and Ford 5.0 V8 insertion - see:
http://www.sky.net/~boballen/mg/Masters/
'74 MGBGT---3000mile/year driver, original condition - slated for a V8 soon
'68 MGBGT---organ donor for the '74
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