Coil wiring HELP !?!

[gazzamuffin]

Hi all,

I need help with a simple question.

I have a S3 elan, and have just re-wired the car with a positive earth.

Do I connect the live feed (white wire) to the positive (+) or negative (-) connection on the coil?

The harness also has a black wire along side the white, where should i connect this to?

Any photos would be useful as picture speaks a thousand words!

Thanks

Gazzamuffin

[Jason1]

For a negative earth = White feed to the positive on the coil and the negative from the coil to the dizzy.

I have no idea with regards to a positive earth? I would guess they are reversed?

[simonknee]

Here is a very simple wiring diagram for negative earths and RVC tacho.

The positive (white) is the upper connection and the lower is the negative which will go to the ignition switch/module of your choice.
For RVC the black wire is most likely to trace back to the tacho.
For RVI tach this is different but since you are doing a negative conversion get an RVI tach sent to Speedy Cables to swap it to negative and RVC.

Simon

EDIT: this is a generic Smiths diagram so it includes gauges we don't have and ignore the electric oil pressure

[RogerFrench]

Hi all,

I need help with a simple question.

I have a S3 elan, and have just re-wired the car with a positive earth.

Do I connect the live feed (white wire) to the positive (+) or negative (-) connection on the coil?

The harness also has a black wire along side the white, where should i connect this to?

Any photos would be useful as picture speaks a thousand words!

Thanks

Gazzamuffin

Since your "live" feed is negative, connect it to the (-) terminal. The black wire is earth (positive), and presumably there's an earth connection in the harness somewhere? If so, you could connect that wire to one of the fixing bolts of the coil clamp.

[simonknee]

re-wired the car with a positive earth.

Ooops, sorry Gazzamuffin I read this as you were rewiring a car that _was_ positive earth.
But you probably mean you are wiring it to _have_ a positive earth.

This got me thinking "why does it matter" since it is just a coil and a collapsing field is a collapsing field.
Googling "coil connections in positive earth" brings up a bunch of MG guys with good explanations.
It will work either way but there is an optimum due to the hot center electrode of the spark plug!

http://mgaguru.com/mgtech/ignition/ig104.htm provides a simple test for the best way round.

You learn something every day!