choosing wire gauge/size for engine looms?

Wiring best practices and loom building technique
Jon K
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Re: choosing wire gauge/size for engine looms?

Post by Jon K »

Keep in mind that the amperage and wire size that DTA refers to is relative to a quality wire such as Raychem 55, etc. They use a nice jacket. Some ordinary 22 gauge wire with crap jacketing cannot carry 10A.
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Gadgetman
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Re: choosing wire gauge/size for engine looms?

Post by Gadgetman »

Very true, and not an area I'd economise on either; there are plenty of good suppliers doing high quality proper automotive cable, (and connectors) at reasonable prices, without having to resort to cheap low spec stuff.

Nothing will make your life hell in an environment like a car quite as quickly as poor wiring and grounding.
ProStockVW
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Re: choosing wire gauge/size for engine looms?

Post by ProStockVW »

Is there any advantage or disadvantage to using a thicker gauge wire? I'm using 18G for the injectors, 12V and ECU, and 20G for the the 3 TPS connections. I'm in the process of rewiring the entire engine compartment and this is an issue I can address now.
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MSEL
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Re: choosing wire gauge/size for engine looms?

Post by MSEL »

The only reason you need 18awg wire for injectors is for strength in the loom. Against is the cost, weight and physical size. At the end of the day copper is a commodity and wire is largely copper so the larger the wire, the higher the cost - assuming everything else (like insulation quality) is the same.

All our looms we make are 20awg mil spec wire for the "average" customer. For professional teams we are down to 24 and 26awg depending on the connectors they want to use and what we are connecting up (obviously coils require larger wiring).
katana
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Re: choosing wire gauge/size for engine looms?

Post by katana »

A lot of the quality loom makers use a mesh like fabric tube stuff with just heat shrink at the ends or where wires need to branch out. Leaves the looms nice and flexible but bundled tight enough. I found a fully 'shrunk' loom can get stiff just like pvc tape wrapped ones - not stickie electricians tape - spawn of the devil that stuff!
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