Electrics Wot wire size

Non Land Rover - I have a fuel pump harness which is knackered. I have some wiring from Halfords which is 8 amp. My fuel pump is 7 amp. Is that ok to fit or do I need to go a lot higher ?

Is there a chart anywhere for UK sizing amp vs wire size ?

Hi

Hope this helps u, know there are far more knowledgeable members than myself

Must confess I would go up higher as length of the wire is also relevant, what size is the existing cable please as that can also give u a general idea

gstuart said:

Hi

Hope this helps u, know there are far more knowledgeable members than myself

Must confess I would go up higher as length of the wire is also relevant, what size is the existing cable please as that will also assist in determining the cable size required

How to Select the Correct Size Automotive Wire

User Rating: 5 / 5 In order for your automotive electrical system to perform properly, your wire must be sized properly based on the amount of current (amperage) the wire must carry, and the length that the wire needs to be. For example, you want to add some flood lights to your vehicle. The...

wiringproducts.com

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Wowzers deep stuff.. I will measure existing..I will be honest its a smidgen fatter than the 8amp I have but about 1/3 smaller than the 20 amp I also have.... Problem is I have no idea how long the wire is from source... assume its pretty much a car length.... This spur off the main harness is less than a foot long so its only that bit I am replacing.

ER1C said:

Wowzers deep stuff.. I will measure existing..I will be honest its a smidgen fatter than the 8amp I have but about 1/3 smaller than the 20 amp I also have.... Problem is I have no idea how long the wire is from source... assume its pretty much a car length.... This spur off the main harness is less than a foot long so its only that bit I am replacing.

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Ur so welcome and indeed can be confusing at times, lol

Assume the fuel pump is on its own circuit, do u happen to know what size the fuse is please , as the fuse needs to be rated lower than the wire so that blows before the wire starts to melt

Another confusing factor I found is some wires thickness can change according to the type it is

Would assume 12 x amps would be fine but would rather that be confirmed by others

Just done this on there voltage drop calculator , hope it’s useful to u , ref connectors I like the ones that have solder inside of where u just heat them up with a flame or heat gun , will find the link for u

Found those solder heat shrink connectors

• 
  
• White Heat Shrink Connectors: suitable for cable/wire 24 AWG - 26 AWG / 0.25 - 0.34mm²
• Red Heat Shrink Connectors: suitable for cable/wire size 18 AWG - 22 AWG / 0.5 – 1.5mm²
• Green Heat Shrink Connectors: suitable for cable/wire of sizes 16 AWG – 18 AWG / 0.75 - 1.5mm²
• Blue Heat Shrink Connectors: suitable for cable/wire of sizes 14 AWG – 16 AWG / 1.5 - 2.5mm²
• Yellow Heat Shrink Connectors: suitable for cable/wire sizes of 12 AWG – 14 AWG / 4.0 - 6.0mm²
• Purple Heat shrink Connectors: suitable for cable/wire size 8 AWG - 10 AWG / 6.0 – 10.0mm²
• Orange Heat Shrink Connectors: suitable for cable/wire sizes of 8 AWG / 10.0mm²
• Mixed sets are 20% White, 20% Red, 20% Green, 10% Blue, 10% Yellow, 10% Purple, 10% Orange

Found the link above that are a lot cheaper along with the colour code according to wire size

Thanks for the help.. I have a load of those connectors, luckily this one has a junction.



Thats the wire in question. I measured it about 2.6mm... I only have 2.1mm or 3.3 wire so will have to source some more I guess... Do you think that will be 2.8mm wire ?

The fuse is 20a so I suspect that would make sense 20 fuse on a cable suited for 25 amp. Assume the insulation will take this up to 2.7/8 it was.

25 AMP Rated 2mm² Single Core Stranded Copper Cable 12v 24v Thin Wall Wire (10M 20M 50M 100M) (BLACK, 10M Coil)​

ER1C said:

Thanks for the help.. I have a load of those connectors, luckily this one has a junction.



Thats the wire in question. I measured it about 2.6mm... I only have 2.1mm or 3.3 wire so will have to source some more I guess... Do you think that will be 2.8mm wire ?

The fuse is 20a so I suspect that would make sense 20 fuse on a cable suited for 25 amp. Assume the insulation will take this up to 2.7/8 it was.

25 AMP Rated 2mm² Single Core Stranded Copper Cable 12v 24v Thin Wall Wire (10M 20M 50M 100M) (BLACK, 10M Coil)​

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As always ur so welcome

Indeed that 25 amp wire should be ok, alas the link has gone , must confess normally buy my bits from 12 volt planet , plus there very helpful if u wish to double check things before purchasing anything

Handy ur able to do it on a workbench and not under the landy, lol, for any extra wires or vulnerable ones so to speak ive put them in conduit as an extra precaution, can also get a Y conduit piece , conduit in split or not

Plse let us know how u get on

Conduit


Conduit fittings

gstuart said:

Conduit

Unsplit & Split Nylon Convoluted Conduit | 12 Volt Planet

Nylon convoluted conduit in unsplit & split versions for protecting cables in low voltage automotive & marine wiring applications. Various sizes available.

www.12voltplanet.co.uk

Conduit fittings

Convoluted Conduit Adaptors & Fittings | 12 Volt Planet

A range of adapators and fittings for use with unsplit & split convoluted conduit in low voltage automotive & marine wiring applications.

www.12voltplanet.co.uk

View attachment 315187

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I like that, the main loom is 43 years old and very weakened so I may well do that as well, wire turns up tomorrow, just hope I can find the new eyes for it.

This is the location, its a pig to get to so glad it disconnects.

ER1C said:

I like that, the main loom is 43 years old and very weakened so I may well do that as well, wire turns up tomorrow, just hope I can find the new eyes for it.

This is the location, its a pig to get to so glad it disconnects.

View attachment 315191

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Many thks and indeed ideal for inside the engine bay or near fuel tanks etc, just that extra bit of protection , often buy electrical connectors in a kit off eBay etc

Split conduit is easier to install, the unsplit is stronger as it does not crush under cable ties.
Last few months I have used at least 200 hundreed feet on one truck, other two guys must have used the same each on the same truck!