Electrics

[Vanden Perre]

Does someone know what this small cylinder is for? It is in the engine bay of my S3 fixed with a screw together with the bracket holding the coil. The wire is connected to ...nothing (!) which does not seems to affect her.
Any clue?
Thanks.
Olivier.

[steveww]

Looks like a condenser to me. Used to suppress electrical interference, essentially a capacitor.

[nebogipfel]

As Steve says, a common fitment back in the 60's and 70's used in the hope of reducing the crackles on car radios.

[Vanden Perre]

Thanks.
Now two questions.
Does this condenser needs to be connected to the earth through the fixing bracket?
To which terminal of the coil should I connect the small wire (see the picture)? To the CB or the SW?
Olivier.

[mikealdren]

Olivier,
The condensor is fitted 'across' the points and it stops/reduces sparking across the points gap. That has two benefits, it reduces the radio interference and it prolongs the life of the points. The body is usually earthed through its mounting in/on the distributor and the other connection goes to the points.
Mike

[schroeder]

Olivier,

Mike is referring to the condenser inside the distributor.

What you have shown is to reduce radio interference as already suggested. This item is located next to the coil and clamped using the coil retaining bracket bolt. At this location there should also be an earth strap grounding this particular bolt to the engine or chassis. Can't recall which but probably doesn't matter.

As for which side of the coil I believe it is the input side. No doubt someone will correct me if I am wrong. Either way it will not make any material difference to the ignition system just may not reduce radio interference. Of course if you do not have a radio or do not suffer interference you can leave it off altogether.

Stu