Wiring loom

[Drew66]

Part of a tangle of wires that are supposed to be my wiring loom. Some have been cut out of the car by previous owner, who hasn't labeled any of them.

Can anyone recognise it and tell me where it goes.

Due to the damage i will have to create a new loom, any help or advice would be appreciated.

[RobPearce]

Unfortunately you seem to have fallen foul of the "non-members can't post photos" restriction.

[Velocita Rosso]

Having just fitted a new loom to a MK3.....I can tell you everything....take my word for it. However which Mark do you have?

[Drew66]

Thanks, I am now a full memeber. 😎

Apparently I am using the wrong browser to paste images, I have had to attached the image as a file instead.

I think this might be the rear wiring loom.

I have a 1978 1500 spitfire.

There are a lot of broken, cut and damaged wires in the looms.

Have you used flag connecters or replaced them with straight connecters.

I am going to use heat shrink to cover the completed looms. which is going to be interesting. Do I use short lengths between the wire spurs or make holes in a longer length at the appropriate positions for the spurs.

Any and all help appreciated. 😆

[RobPearce]

Hi Drew,

You're quite right, that is the rear body loom. It's a little different to the one I've recently fitted as, like Mike, I have a Mk3. However...

The bottom branch in that photo is the bit that runs across the rear of the boot, connecting to the left and right light clusters and the nuber plate lamps in the middle.

The centre branch with the one straggly wire and a bunch of three at the end connects to the fuel gauge sender in the middle of the tank. I'm not sure what the straggly wire is for - it's not there on a Mk3.

The top branch is the connection to the main / engine loom. It looks a bit short to me. It should pass through the left hand inner wing, over the wheel arch, then come out of the B-post and run along the floor and up the left hand A-post to where it meets the front loom near the battery tray (on a RHD car). I'm also a little surprised by the bundle of loose wires there, as the Mk3 loom has a multi-way plug and I'd have expected the later ones to be the same. So perhaps some DPO has managed to cut/burn through/crush the loom under the passenger seat and done a bodge repair.

Holes in heat sink can be awkward to achieve so I'd be tempted to use split lengths. Actually, I'd be tempted to use proper loom wrapping tape, or even invest in a new loom, depending on your budget. But heatshrink can work.

[bodders1]

I agree with everything Rob says - this is a rear body loom.  It should have a substantial connector on the end (and be a bit longer).   When fitted to the car, it has to pass thorugh the cross-member under the passenger seat.  The connector on the forward end is too large to fit though the holes so it should be threaded - carefully - from the front to the back.  It looks like whoever removed it from the car couln't be bothered with unthreading all the wires from the boot end forwards, and took a shortcut by cutting thorugh the loom.

As it appears in your picture, the first branch in the middle of your picture is the part that runs across behind the boot board and connects to your fuel tank sender and boot light.  The remaining brankch (reading left to right) is LH light cluster, number plate light, and RH light cluster.

It looks like it has been cut at a point where the loom leaves the floorpan and passes over the rear wheelarch, where the branch should emerge that runs to the seatbelt switches and the pressure sensor in the passenger seat.  This   https://www.canleyclassics.com/triumph-spitfire-mkiv/1500-body-harness-and-main-harness  shows how this part of the loom should run.

Hope this helps

Bodders1

[Velocita Rosso]

Ditto the above......use harness wrap/loom tape , far better............if yo have to break into the loom for any future problem/needs

[Drew66]

Thanks then the loom shouldn't be in 3 pieces.

I'am assuming then that image 2 is the other half, with 3 being the connecter block and 4 is where it has been hacked.

5 is the main loom with the instrument cluster on the right and the engine compartment

on the left.

But what is 8 is it the fuse panel. positioned approximately half way down the loom.

 

 

[Drew66]

I was looking at hard wiring a Gps tracker and immobaliser into the loom.

[RobPearce]

Quoted from Drew66-

Thanks then the loom shouldn't be in 3 pieces.

I'am assuming then that image 2 is the other half, with 3 being the connecter block and 4 is where it has been hacked.

Yes, that is correct.

Quoted from Drew66-

5 is the main loom with the instrument cluster on the right and the engine compartment on the left.

But what is 8 is it the fuse panel. positioned approximately half way down the loom.

By '8', I assume you mean the sixth photo? With the mating half for the rear loom connector and a bunch of chopped-off wires? The colours of those wires, and their proximity to the rear connector, would certainly suggest they should be connected to a fuse box.

[Drew66]

Yes it is thanks.

Thats what I was afraid of.

Did you narrow down your search for a tracker.

Installation is simple all that is required is a 12v to 5v transformer, a fuse and a couple of wires. Used this to hard wire a dashcam into my daily runner, only cost a couple of £.

 

[Tim Bancroft]

I totally agree with the other posters, use loom tape. Available at all car electrical suppliers.

[Ian Perry]

On "Project Gruyere", I took the rear loom out before starting to weld the NS floor and sills, partly due to the amount of heat and the need to replace/repair the channel in the floor crossmember where the loom goes (as per Bodders' post on 31st, the multi plug won't pass through the crossmember, so I carefully detached everything at the back and threaded it painstakingly through from the back).

The other reason for taking it all out is that it's been bodged and butchered, so I am thinking that replacing it is probably the way forward. I have some experience of rewiring/making new looms having done several in the past, so am confident of doing a serviceable job of it. The rubber multi plug is a small challenge though, as it's a moulded item. I don't at this stage want to pull out the whole front loom, unless I find evidence of further butchery. My options therefore seem to be:

1 - repair the existing loom, cropping off old/broken/ruined wire and 'fishing' new wire on  (solder and heat shrink),

1A - crop the plug off the old loom and just go for a whole new loom 'fished' onto the tails,

2 - buy new old stock (or remanufactured to OEM spec if it exists) rear loom,

3 - get a new aftermarket connector and replace the existing moulded rubber plug completely as part of a new bespoke loom,

4 - use 'loose' individual bullets on a new bespoke rear loom to connect to the existing front plug.

Of these, option 1 or 1A appears most plausible. In making a new rear loom I probably wouldn't bother with the seatbelt warning light switch wiring (I doubt the switch in the seat works in any case, going by the overall condition of the seat)but the rest of is certainly needs surgery looking at the bodgery going on there.

[Ian Perry]

PS I agree on loom tape. It requires patience and a little care (easiest with two people, but possible with one person), but is much the best solution and looks authentic too. And if you need to, you can open up and re-secure/replace using insulating tape to close it/secure it.

I usually tie the loom together first with cable ties, with extra ties where there are cables branching out from the main part. The branches get bound up in loom tape first, winding up the branch towards the main loom, with the tail wound onto the loom and taped down. The cable ties come off just before the loom tape gets there, they just hold it all together until the loom tape takes over. Once the branches are covered, the main run comes down and secures the tails of all the branches as well.

On occasion, you can use a sleeve or heat shrink for specific branches (the individual wires that go to the engine temperature sender and alternator exciter come to mind), but generally I wouldn't bother with it for the main run.

PPS I like to use crimp connectors with separate insulating sleeves, but then adding a drop of solder into the crimped joint afterwards to 'seal the deal' - will last forever then.

Good luck!

[Velocita Rosso]

For the rear section, its so easy to use the old as a pattern, go to a car electrical supplier, buy the six different coloured cables, bullet end them(proper ones not the re/blue shrouded crap) and make your own harness...and you can add another cable or two to feed boot lights etc

Been there done that...until we totally rewired the whole car with new harness  

[Ian Perry]

Hi Michael, yes, indeed - I have loads of the correct colours for everything, which is why I'm reluctant to buy a replacement / remanufactured rear loom.

The tricky bit is connecting to the front loom - if conventional bullet ends will work, that's one thing, but it would - to me at least! - look like something of a bodge compared with using the moulded rubber block. The idea of a whole new bespoke rear loom appeals, in part because I can thread it all through the passenger side floor crossmember as plain wire, and do all the tricky bits once it's 'in' the car.

[Velocita Rosso]

Just de solder /resolder the original joint block to the new cables

[Drew66]

I have complete the rear loom, I used heat shrink and over lapped to create dust proof joints. Removed the seat switches and wired in a Gps tracker.

The only problem I have found is that the colours in the haynes manual, british layland repair and operation manual and the actual triumph garage workshop manual all have different wire colours. Non of which match the colours on my car. lol

Regarding the rubber plug I have found a modern waterproof plug for £7 online, it's approximately half the size of the original.

Now comes the hard part the front loom.

 Is it possible to replace what I am assuming is the positive cable to the speedo. (see photo)

 Any help identifying the connectors and wires in the attached photos would be much appreciated.

[drofgum]

Drew,

That "positive" wire is the supply to the instrument illumination bulb socket. With a little force that socket can be removed from the back of the speedometer. You can then decide whether to solder on a new wire or replace the entire socket.

Cheers,

Paul

[Drew66]

So glad someone knows what they are doing.

Any idear about the rest of the connections. Unfortunately the previous owner stripped the car and didn't put any tags on the loom.

[Velocita Rosso]

The gauge lighting bulb holder can be replaced by a modern plastic version that just push/click fits they are readily available. (Durite?)I did this with my gauges (prior to total harness replacement)

[Drew66]

Yes, I am looking at replacing all the dash bulbs with screw in led's to give it a crisper look.

I really need information on the front loom connections.