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
The ACTIVA, as logical as cubed tumble-weed

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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!
ex BX 1.9
ex Xantia 2.0HDi SX
ex Xantia 2.0HDi LX

C5 VTR HDi estate, 76518762
Out amongst the stars, looking for a world of my own!

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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.

Hope helpful.

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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 :-)