Wire sizes and suppliers.

[Johno]

Evening all, so if making extensions or replacing single wires, how do you know what size they should be and where is the best place to get short pieces at reasonable prices. I'm currently looking at an old wire leaving the heater. Green with white (or yellow). Mk iv Spitfire.

Best Regards Johno

Edited January 18, 2022 by Johno
Typo

[Peter Truman]

Or increase size/rating if going long distances eg alternative fuel pump at rear larger size reduces voltage drop under load.

[Clive]

https://www.ebay.co.uk/itm/153620435709?

Should be fine, rated at 16A. All the colours, with stripes too.

But I, like others, have old looms that supply lengths of wire. And I keep black and red 100m rolls of 16A and 5A cable on the shelf. I seem to have some organge and green too, but can't remeber where it came from.

I have used https://www.vehiclewiringproducts.co.uk and other online sellers too, but delivery is usually £4 per order so gets expensive if you only want a few metres. However, the same cable as the ebay ad is 41p/m  or £8.80 for 30m, so if you want to buy a selection, the savings add up. Plus they are good for fuseboxes, relay etc etc. not to mention decent spade connectors and bullets.

[Colin Lindsay]

6 hours ago, clive said:

But I, like others, have old looms that supply lengths of wire.

I, too, use old looms - the wire is the correct colour and rating, but sometimes it can be brittle through age. It's amazing when you unwrap the insulation off an old loom and uncover the bright fresh colours of cables that have been covered up for fifty years. Those are the bits I try to use, not the exposed areas that have discoloured or weathered.

[RogerH]

Hi John,

Like Clive I also use Vehicle & Wiring Products. TRy and make a list of what you need for now and possibly down the road as P&P is  expensive for a small item.

https://www.vehiclewiringproducts.co.uk/c-48-cables/c-198-single-core-pvc-thin-wall-cable/p-973-16-5-amp-1mm-sq-32-0-20

11amp is their smallest and comes in solid colours

16amp comes in  solid and dual colours

RS Comps do much thinner cables 

 

Roger

[Mjit]

I've used AES too in the past (https://www.autoelectricsupplies.co.uk/)

Oh, and if you go for "thin wall", which I'd recommend you do don't worry that the new wire's thinner than the old one - it's just the insulation that's thinner, not the wire inside

[Josef]

If you strip some of the old wire and measure the diameter of the copper section with a calliper you’ll be able to use something like this chart to figure out what the closest cross sectional area of modern wire you can buy is. There’s enough division between the available sizes that the error that trying to measure the diameter of a bundle of fine strands will introduce isn’t going to matter too much. 

[Johno]

Josef thanks, 

[daverclasper]

11 hours ago, Colin Lindsay said:

I, too, use old looms - the wire is the correct colour and rating, but sometimes it can be brittle through age. It's amazing when you unwrap the insulation off an old loom and uncover the bright fresh colours of cables that have been covered up for fifty years. Those are the bits I try to use, not the exposed areas that have discoloured or weathered.

Well, I was out for a walk with my long term girlfriend recently in some woods and there was an area where some car parts had been dumped, long ago.

There was a loom part buried under old leaves etc. most of the colours were fresh and bright under the tape. Maybe 70/80s, judging from the switches?. She thought I was bonkers dragging it back home.

So the big questions for me, is the copper in the cables likely to be ok, not subject to damp/air oxidation? (or was she right?, not that she's in anyway an expert, just fed up with my  collecting habits)

 

[Colin Lindsay]

1 hour ago, daverclasper said:

Well, I was out for a walk with my long term girlfriend recently in some woods and there was an area where some car parts had been dumped, long ago.

There was a loom part buried under old leaves etc. most of the colours were fresh and bright under the tape. Maybe 70/80s, judging from the switches?. She thought I was bonkers dragging it back home.

So the big questions for me, is the copper in the cables likely to be ok, not subject to damp/air oxidation? (or was she right?, not that she's in anyway an expert, just fed up with my  collecting habits)

 

Hard to tell until you actually see it; if covered by insulation and well away from any exposed bare ends it might be ok, but if water has been running round it for a long time it may have suffered.

Remember what happened when the guy in Amesbury found the perfume and thought: "I'll have that"... for years over here, if you found a buried or covered wire whilst out on a walk you ran away very fast...

 

[Iain T]

A question..can you buy the four headlamp assy wires for a Vitesse with the correct colour coding or is it easier to make them up yourself? I'm leaning towards making my own as I want lengths to run to the relays I've fitted on a bracket where the horns are. 

Iain 

[Josef]

Autosparks don’t list them, I expect they’d probably make them up for you though as the looms are all made to order. But it’s not a particularly hard part to DIY so for the cost / effort ratio I’d probably make them up myself. Only didn’t for the equivalent bits on my Spitfire as they’re identical to those on classic minis so you can get them dead cheap!

[Iain T]

I think I'll make them up myself. Is it a standard H4 fitting for the main/dipped and what are the two mains fittings? 

Iain 

[NonMember]

The original Vitesse headlights are all standard H4 fittings, it's just the the two inners are missing the dip terminal. Mine now has Stag inners, which are H1 and not nearly as convenient.