Thread: New wiring harness, with size?

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Hi !

I want to make new wiring harness in my car, but i'm a bit confused about the sizes.
I dont want to much different cable sizes, so i think about:
Main ground 2 awg
Main power 8 awg
Signal cable around the car 14 awg (Light, dash, wipers, carstereo (just headunit) etc)

How does that sound?

Your choices look good. But I'll qualify that with I don't know what you're loading it with. Things like A/C, electric fans, etc. can really add a huge amp draw. Just be sure to use a high quality wire and connections.

I would think that you'd save money, for sure save a ton of time and end up with a safer installation by buying a replacement harness. Most of the major suppliers advertise for pre-1979 models, and some advertise in-dash harnesses, too. Check KwikWire, American Autowire, EZ Wiring, etc.

Originally Posted by Sherlock_Holmes

Main power 8 awg

Depending on the length of the wire, #8 will usually not be large enough for the Main Power from battery to starter. In most cases #2 is a better choice for the battery to starter, with even larger wire sizes sometimes preferred here.

And, as 34_40 pointed out depending on accessories used and the length of the wire, #8 is usually more than enough for feeding the fuse box and alternator feed, with #14 OK for most accessories.

While making a wiring harness can be fun, it requires a little knowledge and planning, there are several sources on the net for wire gauge/current charts that will help you. And, remember in most areas on the vehicle high temperature/severe condition wire insulation is required, and lots of labeling.

However, I agree with rspears, the safest, least expensive and easiest is a complete wiring harness. Whichever way you decide to go, I suggest you figure the total load and individual load requirements first..

Hi guys

Thanks a'lot for the answers. I may was a bit unclear in my first post.
It's not all my harness i want to change, just some wires, like new wiring for the headlight, mounting some gauges and change some broken wiringen. While doing that, i will make a new cable for the fuse box, main ground and starter

I stick with:
Main ground, and power to starter: 2 awg
Power to fusebox: 8 awg
From the fusebox throughout the car 14 awg

Have a nice day

I would suggest going big and not having a worry down the road. If you have a lot of high draw add-ons (or possible plans for them) going bigger will not hurt anything


Main Ground and starter cables: 1/0
Power to fusebox 8 is "okay" but 4 would be better.
Fusebox throughout car will really depend on the item you are powering. Electric fans want 10 gage, lights and gages can get by with 16 and so on.


Because I have no idea what your experience level is with this stuff I will ask if you have the tools and connectors to do this correctly. PLEASE, do not use twisted wire and wire-nuts to make up this harness.


Once you price out the wire and tools and connectors to this correctly you MAY find it cheaper to simply buy a plug and play harness from AAW. and put it in...
Mark

Twisted wire and wire nuts are a fire waiting to happen. I've used butt connectors in a pinch but I prefer to solder everything though the joint has to be tight. Solder is not like welding since it doesn't penetrate the wire itself. A properly soldered joint will not heat up and adds a miniscule amount of resistance to the circuit.

Thanks a'lot for the input guys !
And, i always use solder when connecting wires

The crimper makes a huge difference.

Get a good ratcheting style crimper. The best your money can buy will say LOBSTER.

I totally agree, i got and old one (from my father) it's does the job 10 times better than the cheap one you can buy on ebay