Check your POSITIVE batery lead!! PICS ADDED!!

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Re: Check your POSITIVE batery lead!! PICS ADDED!!

Post by Stickyfinger » 19 Apr 2018, 23:07

ALL modern cars are Negative Earth

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Re: Check your POSITIVE batery lead!! PICS ADDED!!

Post by Hell Razor5543 » 19 Apr 2018, 23:49

Stickyfinger wrote:
19 Apr 2018, 23:07
ALL modern cars are Negative Earth

They are all pessimistic about the world!

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Re: Check your POSITIVE batery lead!! PICS ADDED!!

Post by white exec » 20 Apr 2018, 07:57

1080 wrote:
19 Apr 2018, 22:19
By the way, which way does 'current' from the battery flow?
From positive to starter?
A question best not asked, in practical terms and in relation to troubleshooting.

The real answer is that negatively-charged electrons (or rather the charge on them) travel from the negative post of a battery, round the circuit, and towards the positive post. This flow of 'charge', large or small, is what we call 'current', and it has the useful ability to do work (heat, magnetism, carrying information, triggering other things...) as it does. The bigger the current, the bigger the cable needed to carry it - to provide adequate electron flow. A good analogy is with water: the more flow needed, the bigger the pipework - and no restrictions (resistances) en route.

Having said that, for circuit design work (and the calculations that go with it), there is a 'convention' of assuming that current flows from +ve to -ve. In practice, this assumption doesn't affect most practical electrical design, it just ensures that everyone is working in the same fashion.

The circuit from battery to starter motor is just that - a circuit, a circular thing. For the starter motor to turn briskly, a large current must flow around the circuit. All sections of this circuit must be able to carry the same large current (300-amps or more), and there must be no pinch points - such as a corroded or poor connection, damaged wiring, or dirty relay (switch) contacts. It is for that reason that ageing lead (Pb) lump battery connectors (which suffer internal corrosion, where the cable strands go black) need replacing after a number of years in service.

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Post by 1080 » 22 Apr 2018, 01:42

That's what I thought. In the past, I've had numerous discussions/arguments concerning this.
Apologies for going off topic...
New earth lead fitted: no more smoking.
Thanks for the succinct explanation Chris :-)

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Re: Check your POSITIVE batery lead!! PICS ADDED!!

Post by Wookey » 12 Jul 2018, 23:03

Right, I had to change my earth cable when it was 15 years old (on an expert van) because it was getting hot rather than transferring electrons down its sleek low resistance. It had probably been doing this for some time before I noticed. Solenoid engagement worked much better once I did this.

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Re: Check your POSITIVE batery lead!! PICS ADDED!!

Post by sparksie » 15 Jul 2018, 01:49

Hi all
I thought I'd mentioned, way back when, that I have the equipment to produce these leads, to a higher spec than original.
I was wondering why nobody ever asked, but now I've read the whole thread again and no such post from me appears to be there.
Sorry guys, I don't know what happened.
If anyone needs a lead made up and is willing to cover my costs, tell me what you need and I'll try to help.
I don't need make/model/year, except as a curiosity. Dimensions are all that matters, along with a pic if possible.
You'll need to arrange collection, or accept the postal cost/risk, but that's still likely to be a significant saving on main dealer prices, especially if you're in Ireland.
I'm offering the service as a sort of thanks for all the help and support I get from you guys and hope it doesn't get out of hand.
I do NOT want to see my leads up on eBay for crazy prices and will have to reconsider, should that happen. I may also be slow, if I'm busy with paid work, so bear that in mind. Don't ask me for a starter lead for a wedding limo in the run up to the wedding, for example.
That said, the negative lead I posted about on here, on the 206, would have cost less than ten Euro. A similar length battery lead less than E15, including the battery terminal, so somebody's cleaning up, judging by the prices people are paying...