Building a wiring loom

[ianmayco68]

Hi all , the wiring loom on my project a 300tdi 90 is has been mucked about with a bit , wires cut in here and there , the dreaded choc blocks all over the place . I know I could buy a ready made one from autosparks but I haven't got £650 to spend and I feel quite confident that I could make one for far less than that , even if I just copy it . I plan to do the headlight wiring upgrade and have already made the looms up for that and I'm thinking of putting the fuse/relay box in the battery box . I know plenty on here have made there own looms , so I looking for advice , tips , do's and don'ts on how best to improve the original loom , all help and suggestions welcome .

cheers and stay safe Ian

[Arjan]

Hi Ian,

Yes, several of us have indeed made our own looms - some real good ones (do a forum search and you'll see some very good ones) and some like mine. 

Everybody has their own ideas, needs, background and all the rest when they decide to make their own. I make mine based on quite a few (rally / offroad) vehicles, boats, aircraft and campers. They're all different. So read, look, ask yourself what it is you want to achieve and make a good honest inventory of your needs before you start doing the sums. Good quality cables, crimp tools, strippers, (multi) connectors, etc. all add up. I've just done the 88"Hybrid and over 260 mtrs. of cable in there somewhere.....

With my looms, colours mean nothing. Everything has been labelled with a number and the database will tell you what it is, where it is located and where it is connected to. With over 590 labels in the database you'll need it. But I'm know for my overkill. 😄

Have Fun !

[ianmayco68]

Cheers Arjan , I've already got all the tools and I've already done the chassis loom and the front lights loom so I thought I'd have a go . I did do a search putting LR4X4 behind but not a lot came up , I'll try altering the wording . I did realise that they would be pretty specific to the individuals needs and what works for one doesn't work for others , it was more advice on the main systems I was after , like is there a better way of wiring the indicators up for instance .

cheers Ian

[sgo70]

I came across this post on a Toyota forum somehow. I ended up ordering one of those waterproof fuse boxes and a pile of the same connectors. I think this should be more than enough circuits and relays and I can mount it under the hood without any worries. Haven't started wiring yet, still trying to paint and reassemble but I have been planning things out.

https://www.fjcruiserforums.com/threads/spod-ha.157834/

 

I've wired a couple of cars and motorbikes and find that doing one circuit at a time and temporarily holding things in place with zip ties works well. Easy to add wires as you go along but uses thousands of ties lol. Once it's complete I want to avoid split loom and use proper tape to wrap it all together, this is a pretty good article.....class D tape is my plan. Maybe use some tech flex braided sleeve in some places but I kind of doubt it.

 

https://www.assemblymag.com/articles/94713-tape-for-wire-harnesses

 

Sean

[Arjan]

Good !

Indicators. We use a electronic "flasher unit" that operated 2 relays and a fuse bank. Every consumer (LED) is fused separately, including the trailer socket. 

Headlamps (H4) have 4 relays + 2 additional ones for optional driving lights. I have several pairs of very traditional H4 - don't like the LED ones for price...

Everything is switched through relays and fusebanks.

These days, modern "motherboards" have all these fuctions in one and save a lot of space and some can be programmed to do almost everything - apart from making coffee....

[ianmayco68]

Thank you both that's great will have a read of those articles later thank you sgo70 . Quite agree Arjan have tried the cheaper LED headlights and I don't like them have just gone back to H4 ones and night breaker bulbs , and thanks very much for the other help .

My thoughts so far are , I've brought a Disco 1 engine bay fuse box , mount that in the engine bay and feed all functions through this . Then I've got one of these  which I intend to use for the front lights ,

and for the main fuse box I've got this ,

all from eBay , don't know whether I'm on the rite lines , I did have a link for a wiring board which didn't need fuses will have to look if I still have it .

 

[ianmayco68]

This is what I remember there was a post about it a few years ago https://motogadget.com/shop/en/m-unit-blue.html .

[FridgeFreezer]

Been there done it on the 127 and the 109, write-ups with lots of piccies below;

109 Wiring re-do with modular fusebox starts here:

127 engine loom / MSEFI install starts about here:

 

If you buy all the right wire colours from VWP it will add up surprisingly fast and £650 will start to feel like a fairly good price TBH, if I had a standard truck I'd probably consider paying it.

Bear in mind a 90 is ~4m long and it can take nearly 10m of wire to get from the tail light to the switch behind the dash by the time you've routed it round, put a connector or two in and allowed some slack, I don't buy less than 10m at a time of anything for that reason, it's never worth saving 35p to find you're half a metre short having spent hours rolling round under the truck tucking it all in!

There's blade fuse holders that bolt almost perfectly where the old glass fuses were if your truck is old enough to have them.

You need a quality ratchet crimper and quality crimps - cheap ones WILL fail and fall off.

You need at least one bag of 1000 cable ties and ideally a cable-tie tensioning & cutting gun to cut them flush so they don't slice your arm later. I use cheap party packs of assorted colours (EG 10 colours in one pack) to temporarily hold groups of wires together and then finalise the loom nipping it all up with proper black ties and cable wrap as required. White cable ties are not UV stable and will ping after a few years.

Glue-lined 3:1 ratio heat-shrink is the dogs danglies.

I bought the VWP party pack Amp Econoseal selection box with crimper and that's a nice thing for making sections of loom unpluggable.

Freelander 1 earth commoning blocks are a very handy thing - 8 spade terminals into a single bolt with a plug-in connector.

[reb78]

Fridge - can you recommend a good quality ratchet crimper, preferably one that doesnt break the bank if thats possible. 

I have a JCB branded one I paid £35 for from B&Q years ago but I am never sure it does as well as it should (or I use it wrong - not sure how). 

[ianmayco68]

That’s brilliant thank you FridgeFreezer 👍 , I’ll have a good read of those , I’ve already done the chassis harness complete with connectors and the engine harness and the auto gearbox loom so it’s just the main loom but as we all know cock that up and the rest is useless. I’ve already got quality crimpers and other electrical tools I’ve brought overtime, loads of cable ties and plenty of shrink tube and terminals and connectors , only things I need to buy are cable which I do have quite a bit in my electrics box and relays who’d have to buy anyway plus even if I bought an Autosparks loom I’d still have to buy cable and bits to wire the extras in like heated screen .

[ianmayco68]

I use this one for econoseal connectors .

https://www.ebay.co.uk/itm/282090702854

 

[FridgeFreezer]

1 hour ago, reb78 said:

Fridge - can you recommend a good quality ratchet crimper, preferably one that doesnt break the bank if thats possible. 

I have a JCB branded one I paid £35 for from B&Q years ago but I am never sure it does as well as it should (or I use it wrong - not sure how). 

TBH mine have come from VWP and been fine - they're not fancy, but they're the right thing for the job and have cost ~£30 a pop ish (one came in the econoseal kit). I've got one for insulated, one for non-insulated (EG relay/fuse housing) and one for econoseal pins - it really does make a difference! I also have a decent quality non-ratchet one which is good for nipping the odd thing up / adjusting uninsulated ones that don't quite grip right.

Proper crimps make a big difference too - VWP don't sell junk but their crimps aren't as nice as genuine Tyco/Amp ones bought from the likes of RS/Farnell although again that gets pricey quickly when you have to buy bags of 100. I've had others just fall off despite being properly crimped - look for the 2nd smaller tube/sleeve inside the end, only the good ones have it. If in doubt, give the crimp a good tug after crimping, better it falls off now than on a rainy night on the motorway!

There's a million very cheap Chinese copies of crimpers that look identical but it's a bit of a pot-luck thing, they might be the same or they might be far worse quality in the flesh.

[western]

Autosparks do a huge range of single & 2 colour coded wiring, all to the standard UK/LR colour codes.

[landroversforever]

If looking at Crimpers I've lots of godd success with the Durite branded ones.

[landy_andy]

I made the new loom for my D100 using primary colour TXL & SXL wire with a heat shrink band to copy the LR scheme, fuse box was from VWP. Connectors are AMP type. Loom is split into sections for easy service & repairs.

 

[monkie]

This is great information. I need to sort mine too at some point. I used autosparks to get the items do build my own engine loom. It cost about 30% less than off the shelf but it educated me a little more about what goes where. I think getting the correct coloured wires is essential for fault finding in years to come. 

[ianmayco68]

Very nice landy-andy, have read through your threads Fridge and lots of useful info in there , and thank you to everyone , first question of many I’ve found the part number for the freelander earthing blocks YPC10004 & YPC10611 the later being the 8 pole one so apart from scrapyards which are no go at the minute does anyone know of somewhere I might be able to buy some from ? Did search internet but got lots of Chinese writing and nowt on eBay .

[FridgeFreezer]

I pulled all mine off a scrap freelander or two while I was pulling the twin engine fans (which fit beautifully on a V8 Defender rad BTW), no idea id they're available elsewhere - if you find a breakers on eBay they might post you a jiffy bag full if you ask?

[ianmayco68]

Cheers Fridge , that’s the answer I was expecting hahaha , but good idea about breakers on eBay better still there’s a 4x4 breakers in Wolverhampton might see if they are still open 👍.

[FridgeFreezer]

For reference, the standard non-insulated spade terminals with the locking tang are what fits those FL blocks, so easy to re-do it nicely. Same thing used on standard relay/fuse holders etc.

[ianmayco68]

Cheers Fridge your a gentleman 👍.

[FridgeFreezer]

6 hours ago, ianmayco68 said:

Cheers Fridge your a gentleman 👍.

You're clearly a terrible judge of character

[volvotgb]

I have wired a couple of vehicles up with these looms :

https://www.speedwaymotors.com/22-Circuit-Universal-Automotive-Aftermarket-Wiring-Harness-Kit,229874.html

https://www.speedwaymotors.com/12-Circuit-Mini-Fuse-Universal-Hot-Rod-Wiring-Harness-Kit,2352.html

On one of them I just used as is and it was fine. On the other, I added a load of extras so I got a modular fuse/relay box and replaced the fusebox supplied. It was still worth buying the loom though. The wire is really good quality and it is all printed on the wiring what each wire is for.

Just another option !

[ianmayco68]

They don't look bad value .

[Giles]

For the earthing, if you can''t find freelander bits, some (all?) peugeots (& other french cars?) of the 80s-90s use 8-way/10-way bolt-on earthing blocks at each corner. Here's a random picture pulled off the internet: https://www.tprneso.com/index.php?main_page=product_info&products_id=229842

Take care