wiring looms (engine) and brittle wires!

[Mark Shutt]

poking around my engine bay there are a lot of brittle wires especially back of engine and I want to replace them whilst I have good access! is there a part loom that can be bought just for the engine? I haven't found one if there is failing that does anyone know a supplier of the correct coloured cables Triumph used for coil/warning light switches etc..?

thanks Mark.

[V Mad]

I find that most of the old looms are quite serviceable, but as you say its just certain parts like the ends that are bad.

You can buy new looms, or you can strip back the black wrapping tape, cut off the bad section (which is usually only the last few inches) and solder on a new wire. When joining old wire, scrape the conductors to get bright copper, then dip the end in flux and tin it until the solder fully flows - then and only then overlap and solder on the new wire after first slipping some heatshrink sleeving over the wires. Cover the joint with the sleeving then shrink it, and fisnish with proper plain pvc wrapping tape (not the stciky stuff). Fit new terminals where possible, although some fittings like certain lampholders are not stocked by the usual suppliers. A proper ratchet crimp terminal is a minimum standard for crimp tools.

You can get all the wiring stuff from companies like VWP (vehicle wiring products) including all the wire colours. I find 32/0.2 thinwall cable is adequate for most circuits and blends in well to the harness.

[Mark Shutt]

You can get all the wiring stuff from companies like VWP (vehicle wiring products) including all the wire colours. I find 32/0.2 thinwall cable is adequate for most circuits and blends in well to the harness.

thanks Chris! this the kind of info I'm looking for, just spent a few hours searching and not come up with much! I'm good with a soldering iron so should be OK with this I want to change all coil wiring and both oil and water temp switch wiring as a minimum, they are cracked all over the place from heat!

Mark.

[V Mad]

Re coil wires, as you will know, Mk2 cars had a special ballast wire in the loom (white/pink) which often gets overheated so check that area. But repairing or replacing that may be tricky so get advice if you are going to do that.

[Robmsharp]

Just one minor addition to Chris's advice - I would recommend making hook joints on the wires to be joined as it will provide mechanical integrity and improve the reliability of the final connection.

[Mike Stevens]

Agree with the above but I would also add to try and use adhesive lined heatshrink. This will give a better water seal into the newly soldered joint.

I use hook joints too. Tin each end. Bend them into a 180 degree hook. Hook one over the other, squash up a bit (to stop the wires falling apart) and re-flow the solder and/or add a bit more.

Cheers,
Mike.

[malc4d]

Looms can be bought from Autosparks

[Rubce]

Make your own. I have made complete harnesses for both our Triumphs

Bruce

[V Mad]

Make your own. I have made complete harnesses for both our Triumphs

Bruce

Did that work out better in terms of price, quality, or maybe you just enjoyed doing it? I couldnt find a source of some of the fittings, such as the bulb holders for the gauges. Any tips on that?

[Rubce]

Did that work out better in terms of price, quality, or maybe you just enjoyed doing it? I couldnt find a source of some of the fittings, such as the bulb holders for the gauges. Any tips on that?

Chris

It depends very much on why you are replacing the harness. If you simply want a like for like replacement then buy a ready made one. If like me you want to modify the harness significantly them making your own makes sense. With regards to the plugs, I converted our over to modern ones. In a couple of instances I spliced a new plug onto the back of the existing Triumph one. If you do a search on the forum you will find a thread I started back in 2009 when I was restoring our Stag. The GT6 was a much simpler car to do as there are a lot less electrics and access is better

Cheers

Bruce

[malc4d]

Most of the stag plugs are still available.

[73stagman]

I would suggest that the looms are subject to total burnout.... Many I have seen have melted insulation and give rise to "strange and almost untraceable shortings" The looms should always be inspected during any restoration as the way the wires are tightly wrapped during the forty year old manufacture means the possibility of the individual wires working against each other as they vibrate or grow and shrink with different heat and cold conditions throughout their life

I have some pics of Brian's wiring somewhere and even the loom we swapped it for had to be repaired before we could use it. Some of the damage is caused by owners putting the wrong wires together but some of it is inherrent in the way the looms were made.
Use the old looms without checking at your peril....

[V Mad]

Ideally you should at least strip off the wrapping tape and inspect the wires, but you can usually spot problems without doing that if you know what to look for. If the tape looks intact, doesnt bulge suspiciously, and looks original its unlikely there are any problems inside. Wires overheating usually shows up near a connector, and is caused by a poor contact - the exception being the ballast wire on the Mk2 looms which can melt insulation inside the loom due to overloading of the circuit. Again inspection of the tape will show melting at some point along the harness.

A friend of mine had an intermittent problem with indicators not working. I eventually traced it to some badly soldered joints. A PO had grafted two different looms together and solder joined every wire, but the soldering was poor. The clue was in the insulation tape bulges that hid the splices.

I still dont know where to get new bulb holders for the gauges - anyone?

[Mark Shutt]

where is this ballast wire that I keep hearing about? I want to fit a new coil (just to tart things up!) but unsure which coil to buy, mine has Luminition fitted..

[V Mad]

On a Mk2 car, find the white/pink wire connected to the coil +

Then trace that back along the loom and somewhere it will be joined to a section of special 'ballast' resistance wire (not copper) then at the other end it will be joined to the white copper wire circuit that comes from the ignition switch.

Buy a good quality, original spec, ballasted coil. My car has an Intermotor coil that has worked well for nearly three years.