37 replies to this topic

[Clip]

I’m about to bite the bullet and rewire the mini. It’s currently a mashup of old and new with a lot of redundant wiring. Its a ‘62 850, but with negative earth, alternator, relays added etc etc, but it’s just a mess. It all works though and haven’t had a single electrical problem, but it looks disgusting 🤮

I’ve managed to source a company that can supply the majority of tracer coloured wires to keep it as close to original as possible. But before I start pulling it all out, any suggestions or tips would be greatly appreciated. 

[madalicesdad]

Label all wires and take photographs, loads of them. Cover where the wires start, end, split and how they are routed.
If the route is awkward behind panels, tie a strong string to the cables when removing and use this as a pull through when replacing.
Make notes and take photos of connector types

[stuart bowes]

tie a strong string to the cables when removing and use this as a pull through when replacing

 

particularly the part of the loom that runs from front to rear

 

I also decided it was daft for the rear loom to come out into the engine bay through the big hole, take a left turn then go back through the bulkhead, so I rejigged the split off point, and now it's all inside the car.  if that makes sense.  Tidier engine bay, all hidden behind the dash, replacing the duff old connectors with one nice new 10pin connector

 

Also, got rid of all the old glass fuse inline fuse connectors which are always rubbish and were not even necessary because the circuit was already fused, why introduce another point of failure.. added a short piece of single to maintain correct length and did proper solder joins at each end so no-one will ever have to go back to it

 

done the basic clean up / continuity testing / full labeling / replacing some of the more duff old cables / re-wrap but I'm going to undo some of it and rewire a few bits, full plans include (just to give some ideas for anyone who's interested)

• changing the fuse box to blade type because they're easier to get and look better (done)
• split the loads a bit with an 8 way box and also use that to have a few spare ways (done)
• Wire fresh supply for spots with relay connection point and dash switch connection (done)
• Added head unit power (live / earth / igntn. switched live)  (done)
• Use pre-existing headlight power leads as a relay switching point, and run fresh new supplies via that relay point with thicker cored singles
• Add a USB power point connection up front
• Add 2 x USB power point connections one for each companion bin (supplied via relay from battery point in rear, relay triggered by one of the green switched lives) probably just use new style blade type inline fuses for those 

Rear Left / right speakers I will probably wire separately from the loom and have that running over the drivers side door away from the main rear loom to reduce any interference (which would probably be minimal anyway but it's just a matter of principle)

Edited by stuart bowes, 30 August 2022 - 03:20 PM.

[bpirie1000]

I may also suggest buying a test light and noting down which wires are ign live, constant live or earths...

Photos and notes are a must have...

[timmy850]

I’d be tempted to start from scratch with a universal hotrod kit, so you’ve got a decent fuse board with integrated relays etc. Ditch all the bullet connectors and use decent waterproof ones like the Deutsch or similar

Something like this, but with an appropriate amount of circuits for a mini
https://aeroflowperf...niversal-wiring

[sonscar]

I am with Timmy above.Do not try to replicate what is already there.Break it down eg wire live to fuse box and relay board,wire everything the engine needs to run,wire the starting and charging circuits,wire the rear lights and then front lights.Be methodical and you may be surprised how easy it is.Have fun,Steve..

[Spider]

If you want a really neat job of it, first work out the individual wire route lengths to each item. I'd suggest working from one place, the back of the speedo I find a good place on these models. Get a piece of wire, say around 1.5 sqmm, route it from the speedo to say the fuse block take off point, mark it, then measure it on the piece of wire. Do that for each and every item, including the inside of the car.

Grab a sheet of pyne board,full size, lay it on the ground, then in the middle near the top (about 600 mm down) make a mark which will be the speedo. Put 2 wood screws, about 50 mm long in about 15 mm apart, so that ou end up with 2 posts, about 40 mm above the board, then come down from that and draw out the route of the loom on the pyne board sheet, at each bend, put a screw in leaving a post and likewise, where you have a take off, 2 screws again for that.

Once you have it all laid out on the sheet, then start running wires on the sheet, give yourself some extra on the ends where you'll be fitting lugs etc.

Once you have all the wires on the board, then start from the speedo and say every 150 - 200 mm lay a band of tape around the wires, you may even wish to use cable ties at this point, then you can pull and push the wires to get them in to a neat bundle. You can leave them with the tape bands (or if you used ties, apply tape and snip the ties off) or from here, get proper loom tape and tape the loom up, but be mindful of the bends etc as once it's loomed up, it;'s not going to want to bend too easy or neatly.

Once you have it taped or loomed up, fit it in to the car and then fit your crimps.

A word of caution though, it is a VERY expensive way of doing a loom. By the time you buy the various coloured wires, decent crimps and plugs etc and the tooling to correctly crimp the wires etc it will end up costing 5 - 10 times what you can but a loom off the shelf for. You might be temped to use a 'universal' cheap crimper but you'll very quickly regret that. Expect this to take a few weeks too. I can get all the stuff for doing looms at trade (which is about 70% off what you'll pay over the counter) and even then, just the wire is the better part of a grand.

Get in touch with Paul at Vinwire. He has standard looms but he'll make what ever you want for very reasonable money. Anything non-standard, just be sure to show him (a diagram is best) where it needs to go and give him measurement from something else in the loom. Also, I don't know why, but he doesn't supply grommets with his looms. be sure to ask for them.

[PoolGuy]

I’d be tempted to start from scratch.  Ditch all the bullet connectors and use decent waterproof ones like the Deutsch or similar
 

 

 

A word of caution though, it is a VERY expensive way of doing a loom. By the time you buy the various coloured wires, decent crimps and plugs etc and the tooling to correctly crimp the wires etc it will end up costing 5 - 10 times what you can but a loom off the shelf for.

I prefer to build looms from scratch too, but as mentioned can be expensive to tool up for and buy cable. My approach is to use single colour cable for the whole loom, 100m reels of single colour are relatively cheap and you only need 3 gauges of cable (plus the odd lengths for the battery and main feeds to the fuse box. I use heat shrink to colour code the ends of the cables. Also the crimpers for Deutsch connectors can be bought for a reasonable price, Iwiss make very reasonably priced tools which are perfectly adequate for the home user. Also I avoid soldering connections as I much prefer proper crimps (can of worms I know, but it's what I prefer).

 

The above isn't suitable for everyone, but don't dismiss all of it until you've looked into it.  HPA have some great videos on the subject  https://www.youtube....y=hpa101 wiring

[weef]

The early Mini  had quite a basic wiring loom and with your vehicle having an alternator fitted negates the need for dynamo and associated voltage regulator wiring. 

If you want to keep things as near to original as possible then go for the correct wire colour as this makes things easier to follow when lacing up your loom. There will be no relays involved and it only has a two fuse fusebox  

The modern thin walled cable available makes for a neat tidy loom and use the crimped non insulated terminals/bullets with shrowds.

All the parts are readily available nowadays and there are plenty of loom tapes/conduits and sleeving to make things look good.

My best advice is to really study the wiring diagram before you start to get in your mind what goes where because there is nothing worse than having to add a forgotten wire into a nicely taped up loom.

If you do not have the skills/confidence to tackle this operation there will be companies who will supply bespoke looms to suit your needs.

Making up the loom yourself may not be the cheapest way to go but is is nice when you lift the bonnet and think "I did that".

[KTS]

if you are planning on getting stuck in to rewiring the car i would recommend investing in a power probe,  they're not cheap, but are very useful for testing and troubleshooting

[Clip]

Thank you all for your suggestions. I’m really glad I asked because there is so much in your posts that I hadn’t paid much consideration to or even thought of. I’m pretty competent with electrical work and have the tools and equipment, but have never tackled a full wiring harness. Lots more to think about now, and that’s good as I sometimes tend to jump head-first into projects and that’s not good, especially with this sort of work! 

[Clip]

Tomorrow I’ll post some pics of what’s there now to show the situation that I’ve got. 
thanks again guys.

Edited by Clip, 30 August 2022 - 02:31 PM.

[Clip]

if you are planning on getting stuck in to rewiring the car i would recommend investing in a power probe,  they're not cheap, but are very useful for testing and troubleshooting

I have one along with a good multimeter. Agree that a power probe is a great investment, it has saved me heaps of time and frustration. 

[Spider]

A couple of points I missed in my first post.

 

You can try and build the loom in the car but there's just no way you'll get it neat and get that manufactured appearance to it.

 

Noted the idea of moving away from the standard connectors. Yes, there's much better connectors about these days but you're simply not going to get away from all the old ones, items like Headlights, Tail Lamp assemblies, some of the Front Parkers, Instruments and many other items, no matter what, you are already locked in. Then there's items like the Blinker Switch, yes, you could change that, but then you have something that's not 'off the shelf' replaceable, you'll need to buy your new Switch, change the plug and void the warranty on it in the process then fit it. I'd suggest having a good look over all the items in the car (and those you'd like to move to) and think each item through here.

I've found with old harnesses, the wire itself gives little trouble, it's the old connectors, in particular the multipin plugs that do give trouble. I've also found that when new, all these same connectors, including the bullets, when new give zero trouble and do so for a very long time. I think the modern sealed type of connectors came in to vogue in newer cars as electronics were added to them as a Computer is much more fussy and needs good clean signals, many of which are at a 'low level' than say the 20 or so Amps you need to run your Lucas Headlamps.

 

 

I prefer to build looms from scratch too, but as mentioned can be expensive to tool up for and buy cable. My approach is to use single colour cable for the whole loom, 100m reels of single colour are relatively cheap and you only need 3 gauges of cable (plus the odd lengths for the battery and main feeds to the fuse box. I use heat shrink to colour code the ends of the cables.

 

The first loom I made (and made many errors, but also learnt a LOT from), I did in a similar way, single coloured and marked ends. Fair play if you are happy with them Mike, knock yr socks off   but I gotta say, I found I didn't like it. I found the marked ends easily damaged and after a while, some became hard or impossible to read, not for any of them being some cheap and nasty thing, but the environment they were in, especially in the engine bay. It also meant for me, absolutely everything I needed to refer to my diagrams and notes to see what was what, where as with the colour coded wires I know them by memory and I seldom need to refer to anything (only for wipers) to know what each wire is. Purely as a vanity thing, I also didn't like the appearance of the loom having all the same colours in it, sorry to say it this way, but it looked really 'home made' but I stress,,, that's just purely vanity !!
 

[Avtovaz]

cant you just buy that loom?

 

one like this maybe?

 

ive just rewired my bmw engine for microsquirt and its got a volvo engine in it. I used 32;s wire, but i had all the bits i needed at work. You need crimping tool 100%, all the different colour wires, bullet connectors or what ever, it all adds up really quick. Be easier to mod that loom i would have thought to your needs? There also is nothing wrong with glass fuse boxes. 

Edited by Avtovaz, 30 August 2022 - 08:19 PM.