Thread: What's this wire do please?

It's the connection that allows the points to 'fire' the coil (or low tension lead).

Colin

Because a picture paints a thousand words,
and I like pictures.

[ame]https://www.youtube.com/watch?v=W94iksaQwUo[/ame]

whitehillbillies

Originally Posted by whitehillbilly64

Because a picture paints a thousand words,
and I like pictures.

https://www.youtube.com/watch?v=W94iksaQwUo

whitehillbillies

That explains it very well. I'll forgive them for the way they think the current flows and the term 'back EMF' which isn't technically correct. The high voltage is produced by inductance - the colapsing magnetic field in the coil caused by the points opening, which causes a high voltage spike to be induced into the secondary circuit, but that's just me being a bit Electrically OCD...

Originally Posted by Homestar

That explains it very well. I'll forgive them for the way they think the current flows and the term 'back EMF' which isn't technically correct. The high voltage is produced by inductance - the colapsing magnetic field in the coil caused by the points opening, which causes a high voltage spike to be induced into the secondary circuit, but that's just me being a bit Electrically OCD...

It isn't OCD.

Its CDO.

That way the letters are in the correct order...

As stated, it is the low voltage wire and a key part of the ignition circuit. It could be either an internal break in the wire, or possibly the terminal on the coil is not making a good connection, and make sure an uninsulated part of the wire cannot touch anything it should not.

Most likely, in my view, is a faulty connection between the wire and its termination on the coil.

John

all good and thanks to all as usual.


That diagram explains it for me beautifully. I couldn't see it from the wiring diagram. I'll take a look at that lead.
cheers,
David.

The wire was cable tied to the heater cable and the insulation had worn through - both spade terminals look ok but I cant think that the wire would have been earthing through the cable as I would have thought I'd have seen sparks. I'll replace and see what happens.
cheers,
D

further to this - I chopped the offending break in the insulation out and soldered the wires back together and wrapped some insulating tape around it , pending a proper replacement. All good - fired up ok and I took it out for a drive. Chug chug chug after around 5 minutes drive so I dropped speed and limped back home. Went to take the wire off and it left the spade terminal behind attached to the distibutor - so I reckon it was hanging on by a wire or two. Put a new terminal on it soldered and crimped and all good. Runs fine.
cheers,
D