Bulk wire sourcing

[Vertigo]

Hey. Gonna start on my big rewire job soon, and Ill need a lot of colored wire. Where can I source like 15m each of as many colors as possible? Looking to use 14-12AWG for my current carrying stuff (to handle big loads like pumps, and lower loads too just for simplicity), and like 22-18AWG or similar for relay triggers and signal wires. As an aside, I am going to try using Cat6 SFTP network cable for the CAS VR sensor lines - double shielded

So yea, where can I get bulk wire like this?

[GDII]

This is probably a very expensive way of doing it but might allow for all the different colours you need.

Purchasing a LINK or Haltech 5m loom then using that. This obviously only covers the engine so not sure what else you plan on doing.

[Bling]

Ali-Express?

[Vertigo]

This is probably a very expensive way of doing it but might allow for all the different colours you need.

Purchasing a LINK or Haltech 5m loom then using that. This obviously only covers the engine so not sure what else you plan on doing.

Actually, already planning to do just that (Link 2.5m loom), and TBH its not a bad deal at $230. But as you say, only covers from the ECU to the engine, and I need to do the power distribution side of things, from the relay panel Ive made, to the alternator, starter, pumps, coil and injector feeds, and various grounds, and then relay triggers.

The other option is just to get one reel of wire, and label the ends - lol.

[whynot]

You could look at using low voltage control wiring. It's very common in industrial electrical. They have either multi color wires or numbered wires inside a cable. You can get them shielded too and in bundles upwards of 16 pairs. Perhaps visit some electrical installation companies with a few beers and see if they will let you have a look in the scrap pile.

It might not be as flexible as automotive stuff depending on what you got but could end up being almost free.

[matt dunn]

Why not just go to the local auto electrian and buy what you want? Surely they sell it in different colours and sizes?
I know we do. There is not an endless amount of colours in all the sizes, but quite a decent range.

Otherwise go and pull some looms out of some cars at pick a part or something and strip the wires out of the loom.

[Monsterbishi]

Pick-a-part is my main source, it's $40 for any harness that's 3m or longer - I just go there, find a newish car with the longest, thickest harness I can find, and remove it.

For high current cables I've spent the last few years using repco's now defunct clearance website and bought up anything that was cheap...

[Malcolm]

honestly, if you're going to go to the effort of a signficant rewire it's not all that smart to use a bunch of different wire types that aren't designed for automotive use. The major issues tend to be around insulation temperature ratings and resistance to common automotive fluids. Although in the past I've used wiring I've stripped from old wiring looms, I wouldn't do that any more. It's just not worth the hassle if it turns out a wire had damage that you didn't notice.

If you want OEM type wire, then you can get GXL wire from Wirebarn.com in many colours and sizes. GXL is rated to 105degC from memory, and is an SAE standard for production cars.

If you want to go to a motorsport spec wire, msel.co.nz sell M22759/32 mil spec wire by the metre in a multitude of colours (call them if you want more colour options than what's listed on their website, they do lots of different stripe combos too). Once you get larger than 18awg you don't get many colour options without buying largish quantities

An option that many people do to avoid having too many different colours is to just use one colour, but then use short heat shrink bands to colour code each wire at either end.

I would be mindful about overspeccing all of your wire gauges just for fun, not only does it add weight, cost, bulk, and make your harness increasingly inflexible; but it can cause problems with being too large for the terminals in your connectors.

Make sure you do a good plan before you start, and update it as you make changes during construction (at the least I do a numbered connector list in Excel with the pinout of every connector, with the name, gauge and colour of every wire and where the other end of it goes to). Remember you will no longer have OEM wiring diagrams to rely upon, and in a year's time you will have forgotten everything you did, so do future-you a favour and keep notes!

[Vertigo]

Thanks for that great response. I have already revised my target wire gauge from 12 to 16 due to some measurements that confirmed it was overkill. I agree that if Im going to do this, I need to do it right. Here is the wiring plan Ive been revising for the better part of a month or so..

https://i.imgur.com/I3nYLJi.png

Getting there. I just got my Megasquirt back and have prototype wiring for the CAS + COP ignition system, and just tested tonight in wasted spark mode - it works finally, but sounds like its firing on two. Will work on that. But the basic concept is sound, now.

Thanks for the suggestions of loom extraction from parts cars, but I want fresh wire to rule out any variables.

Been recommended Pan Pacific, Ill give them a go.

[Malcolm]

Looks like you've made a solid effort to get it mapped out. What software did you use?

Looks like a slightly unusual connection on your starter solenoid? Are you using a transistor to drive it, and a relay to trigger the transistor?
Do you have diodes on all your relay supplies, or have you just used the wrong symbol for a fuse?
It seems a bit overkill to use separate relays and fuses for the injectors and coils. For calculations I'd usually use 1A per injector max and maybe 2A per coil (depending on the coils), and I'd run them all off the same fuse and relay that powers the ECU and any other engine electronics, but that's just me.
Are you sure a 15A circuit is enough for your fuel pump and IC pump? I think a typical factory fuel pump would draw around 5-8A, and anything like a walbro 255lph or similar gets closer to 10-12A. Intercooler pumps I've worked with tend to be 3-10A depending on type.

Other thing I would note is that it looks like you have some splices on some high current (i.e. thick) wires, notably the positive battery feed. I find it's very worthwhile to give some consideration to how you're physically going to do those. Splices tend to be one of the most failure prone parts of a wiring loom, and they can be tricky to get right, especially on heavy gauge wires. A couple of my preferred options are to use something like this:

http://sealedbussbar.com/Product-Info.php

Or do it all in a single crimp using one of these crimp links
(can just get them from JA Russell). If you happen to know any electricians they should have a crimp tool for doing them (usually something like this http://www.partzonline.co.nz/cable-crim ... 17685.html)

[Vertigo]

Thanks for the advice, and youre right, the high current cables will need to branch off at some point. Currently I have the battery relocated to the front, with big cable running to the factory positive battery terminal junction and wrapped in many layers of tape, lmao. Ill be relocating to the boot to lower the voltage drop (not that there will be that much) and to free up some cable to use for other things. I like that junction block you posted, good idea. The starter cable is going to tape off the B terminal of the alternator for simplicity.

I did some trial and error testing of fuses while running various pumps to determine current, and seemed like 7.5A fuses ran each of the pumps without blowing. 5A blew within 10 seconds, at least with the fuel pump. Its an aftermarket high flow type, fairly loud. I dont have a way to measure current, sadly, as I blew the fuses in my multimeter at some point in the past, and need to visit Jaycar for new ones.

Good eyes, yea some of the symbols are wrong, but are more for indication than accuracy. No diodes, just fuses. Im using Fritzing to do the schematic. Really good, but the fuse symbols are massive And the starter solenoid is the factory one, but afaik it grounds to the starter itself, so I felt a transistor symbol more accuracy reflected the wiring. Squint required

On the alternator, Im unsure whether to run seperate wires for the voltage sense and ignition kick. Never done an alternator before, whats best there?