Still confused about coil markings

[frearther]

Can someone explain in extremely simple terms how my coil should be hooked up?
Data: Coil is a Pertronix "Flame Thrower"; car is positive ground; points and distributor ignition, Elan S2 1966. It ran with this setup two years ago before I had to rebuild the engine and subsequently lost the little tags on the wires..
There are two wires to the coil: one, I presume goes to the tach; the other is the primary wire to the distributor.
Problem: the shop manual shows only "SW" and "CB" terminals on the coil. Which is positive, and which is negative? In other words, which wire goes on which terminal?
I've tried to do an archive search on the subject but haven't found the right search string to get what I want. Please help me before I tear out what little gray hair I have left.

[RichC]

SW = switch
CB = contact breaker

[RichC]

i.e. switch = wire to ignition
contact breaker = wire to distrib ...........but i guess u got that ?

[neilsjuke]

Think of the Dist as the earth so if your car is pos earth the + terminal to the dist.
Neil

[paddy]

Apparently there is a difference between a coil for -ve earth and one for +ve earth.

(See here: http://www.britishcarspecialists.com/pd ... basics.pdf)

The flamethrower coil you have is probably designed for a -ve earth car. So this would normally mean that the terminal marked SW is the +ve, and the terminal marked CB is the -ve.

So on a +ve earth car, the correct wiring would be:

SW -> distributor
CB -> tach

I son't suppose you have a datasheet for the coil? Is a Pertronix flamethrower the same as an Aldon flamethrower?

If you don't know for sure there are further suggestions as to how to tell the difference here:

http://www.mossmotors.com/forum/forums/ ... 11030.aspx

Paddy

[memnon]

Petronix is the brand that Aldon re-brand, so its a good assumption

[frearther]

So it's positive ground car, positive coil terminal to distributor. Thanks, guys.