Making my own main loom/harness

[FridgeFreezer]

Well I'm not going to create a long post about it as I've already kinda done that when I re-wired the 109 from scratch, again, recently;

(re-wiring starts on page 9)

 

Or here: http://fuddymuckers.co.uk/wiki/doku.php?id=eddie:rebuilds:refresh19:12_wiring

Although I haven't finished writing all that yet

 

You can see most of the stuff I used - nothing fancy, just a lot of patience and being willing to spend an extra few bob / extra few hours to do it right. No expensive parts or tools, but no cheap junk or cut corners.

My favourites; Porta-Sol gas soldering iron, glue-lined heat shrink, Tesa non-sticky loom tape (sparky tape is for temporary labels only), bag of 1000 small cable ties for temporarily getting stuff loomed up, pack of assorted colours of cable ties for bundling things together for later tidying (EG blue tied bungle goes to front left lights, green bundle goes to engine, etc), cable tie tensioning gun / flush cutter, VWP party pack of Econoseal connectors + crimper, VWP party pack of P-clips, proper ratchet crimpers for insulated & uninsulated spades, party pack of grommets.

 

@landroversforever - crimp then solder is OK (but unnecessary), it's solder then crimp that's the problem. Crimp Vs solder is an internet holy war for the ages, either done well is fine (and NASA use both), just remember that a soldered joint in wiring wants a bit of support (glue lined heat shrink for the win) to prevent it cracking with vibration. As TSD once said - everyone wants a good crimp but no-one's willing to tug on the wire to find out

 

[monkie]

This is all very helpful stuff. Thank you very much @FridgeFreezerand @landroversforeverIts this absolute golden advice that makes this forum the best resource for help.

When I've done electrical work previously I crimp, solder (minimum amount - not a blobby bird s^*t) and then heatshrink. I don't have a proper econoseal crimper so this is a top tip I will try and source one - typical this all happens in the last run up to Christmass. I hope I can get one whilst I am off work over the holiday period.

[Sigi_H]

13 hours ago, simonb said:

Solder them after crimping for double insurance.

Absolutely not. The hot solder is soaked with capillary forces into the single lines. Where it stops, the cable will break beside the connector due to vibrations. I experienced this on my motorcycle loom.

Edited December 18, 2020 by Sigi_H

[landroversforever]

This is the durite one I've got: https://www.amazon.co.uk/RATCHET-CRIMPING-SUPERSEAL-TERMINALS-0-703-51/dp/B00A692OR

Showing as about £50 on amazon but I'm sure mine was less from the local Durite stockist.

 

 

[daveturnbull]

If you watch Binky, they went for crimp. Having done a fair bit of wiring in the past year, I'm inclined to agree that a good quality crimp has the edge.

[monkie]

My new Lucas dash warning lamps arrived at the old one was faded and corroded. The 12v ones are silly prices as someone bought them all up from Lucas so they only had the 24v type left. Apparently the only difference is the bulbs. 

This is 1 of only 2 that was left at the supplier of the 24volt type. The gent who sold it matched the old Lucas price of £80 and included the 12v bulbs. 

 

[monkie]

I have discovered some wires which I think (hope are unused) so might have some pictures coming up to ask for help to identify, but in the mean time I came across this absolute gem of information so wanted to share - I appreciate it is for a 300Tdi, but it is a great resource:

 

https://www.lrworkshop.com/wiring-looms/defender-1995-300tdi/bulkhead-loom-300tdi-rhd

[monkie]

I'm trying to identify all of the relays on my main loom - I have 5 (I will be adding a glow plug timer relay and two relays for the head lights). I am confident that I have identified 4 of them but would like some help please:

1 - (inside the fuse box area) Starter relay - no questions.

2- (inside the fuse box area marked LP110) Flasher relay (I assume this provides the flashing function for either the direction indicator and the hazard warning?) Is this true?

3 - (inside the dash marked PRC4427 Voltage sensitive switch) for rear window heater - no questions.

4 - (inside the dash with the following wires coming from it; brown, black, blue, blue) - I'm figuring from the wiring diagrams that this is the rear fog inhibitor; how does this work as I can't figure it out from the wiring diagram in the Haynes and do I need it?

5 - (inside the dash with the following wires coming from it; blue/white, black, blue, white/green) - is this to do with the dim/dip circuit? If so, I have disconnected this, so can I ignore it?

I've drawn up my interpretation of the lighting circuit in the standard form (exluding the dim/dip circuit). I can't figure out what role the rear fog inhibitor (if it is such a relay plays).

 

 

[FridgeFreezer]

I assume you have the standard wiring diagram to hand with all the wire colours etc? Or do you need someone to post it up?

[monkie]

8 hours ago, FridgeFreezer said:

I assume you have the standard wiring diagram to hand with all the wire colours etc? Or do you need someone to post it up?

I'd gratefully receive any information please. The wiring diagrams I have (land rover 90/110 manual and Haynes) seem to be quite generic the deeper I go in to the details. 

[western]

The TD Inc 200tdi diagrams should be in here, I have posted them a few times. 

2links in this thread to wiring diagram from the genuine 90/110 workshop manual 

 

[monkie]

I've got a White with purple trace wire in my loom and I can't figure out what it is for from the diagrams. Anyone know what this wire is for?

 

[western]

Only White with Purple I can find is for twin fuel tank circuit, from rear tank with I ternal pump to the relay, doubt these exist on your 110. More likely a unused wire for petrol engined or twin tank vehicles

[western]

Found another White & purple trace wire from a fuel pump isolation relay to a multi connector on the 1991 on wiring diagram.  See items 34 & 40 below. HTH

[monkie]

Fantastic, thank you Ralph. That makes sense. I'm figuring out what wires I am adding in (for head light relays and glow plug timer relay) and what wires I can delete from my loom - This is one of the ones I can delete. I have found a few differences in my loom to the circuit diagrams I have. One of which that had me stumped for a bit is the yellow/black wires. I have figured that the brown/red wire from the glow plug feed goes to a connector and then becomes yellow/black for the dash warning light for glow plugs.

I'm now commited to this and there's no turning back, although I think I'm beginning to discover why you can charge £600 for a new loom!

[monkie]

As my 110 (October 1988) is getting towards the Tdi era, I think my loom does have a few "Tdi-isms" in it.

[monkie]

... And I wondered why I had fuse problems, thank you previous owners for splicing in different coloured wires when you upgraded the fuse box! 

 

[western]

Yellow/black is from glowplug [relay on Tdi engined vehicles] to dash warning light. & the thicker yellow/black from timer relay to N0 4 glowplug

the Brown/Red trace was glowplug feed from ign to No 4 glowplug on TD models,  I removed this wire from my old burnt loom & used it to power my headlight relays direct from Alternator output via 30amp fuses.

your 110 is only a 13 months older than mine [built Sept '89]  I had to replace the complete dash loom back in 2006, I bought a autosparks loom.

that fuse box & 'new' wires is a right mess.

IIRC the TDi glowplug timer relay sub loom & the daisychain part between the glowplugs can be bought ready made & will plug straight in.

 

[monkie]

Here are some pics of the glow plug dash light wiring. You can see the yellow/black wire from the dash light goes to a moulded connector and joins to a brown/red as per the circuit diagrams. There is also an unused yellow/black. 

I'm beginning to think this loom may not be original and could be a later loom someone has retro fitted. All the wiring at the fuse box has been extended by a few cm. As you say it is a right mess and well overdue an overhaul. I am doing as per the advice from FridgeFreezer and others, taking my time, replacing connectors with super/econoseal, using a proper durite crimping tool and methodically mapping where everything should be. 

I'll keep on plodding onwards. It would be nice if it is all back in by the end of Jan as a target. 

 

[monkie]

1 hour ago, western said:

IIRC the TDi glowplug timer relay sub loom & the daisychain part between the glowplugs can be bought ready made & will plug straight in.

As I understand the diagrams (I have a Tdi relay I acquired a few years ago and fortunately had the sense to keep it safe) I need a white wire from the ignition switch, a white/red wire to the ignition switch, a thick brown feed from the live bus on the starter motor solenoid, thick yellow black to number 4 glow plug, a thin yellow/black to the dash warning light and a black wire to earth. Then I should be in business with proper timed glowplug heating. 

[western]

That looks the same as my TD loom, when the 200Tdi was fitted the warning light connector yellow/black wires were altered to allow the timer relay to operate the glowplug light. 

Yes those sound correct. 

 

[sgo70]

Not sure what year these diagrams are for but I've been referencing them while I'm doing my harness. Mines a 2001 110 with a GM engine, Mini Cooper seats, aftermarket power windows and door locks and a keyless ignition so I gave up trying to color match the wires and have just drawn up my own schematic lol.

 

https://duud.ee/LR-manualid/300Tdi_Wiring_Diagrams.pdf

 

Sean

[monkie]

Thank you for that information, those diagrams are for later models than my 110, however there is some commonality and the wiring colour codes are helpfully set out in those diagrams. 

[monkie]

Another question, I don't like the idea of the quantity of unused live wires in the 110 running all over the place. 

Has anyone added in fuses to protect originally unfused items like the glowplug circuit and other items? 

[western]

Need to measure the glowplug amp draw to figure out what fuse rating you would need,