New Wire Harness Opinions

[tiiM5]

Colleagues- I thinking of installing a new wire harness as part of repainting engine bay etc.
I'd be interested in hearing experiences and thoughts on products used.
Are new harnesses braided? Do they come with color coded wire or other identifying methods with
good instructions? As I take things down I realize how poorly color coded many wires are which
has resulted in time consuming tagging with photos.
Will new harnesses with instructions be better such that little mystery is encountered?

Thanks

 

[Jim_Gruber]

Braided or vinyl wrapped. And they follow a specific color code. Wiring diagrams that are color coded can be ordered by year if your car.

 

[Rut]

Tell us about your car! If the wires are in good condition, but the wrap is ratty you can order the blue wrap from Moss. The wires will clean up really well with lacquer thinner and you'll be able to trace them by color. It's a good idea on any old car to clean the connectors and grounds and reassemble with dielectric grease. These are basic wiring systems and good connections make all the difference.
Rut

 

[twas_brillig]

we're reassembling a BE that we've owned (and stored) since 1972. It is being updated (disc brakes, Datsun tranny, 1275 cc, wheels/tyres; panhard rod; LED tail lights; etc.) so will not be concours. Our other BE (running off and on since 1972; our only car for a couple of years in the mid-70s) has never given us electrical problems with the original harness. We also have a Meyers Manx clone dune buggy that I wired up, using the factory wiring diagram for the BE as it was simple enough that I could understand it. However, we're spending a small fortune for this car, and have ordered a harness from Advance Auto-Wire.
The gist of my message is: the original harness has worked fine for us. Get a copy of the original wiring diagram, and duplicate it as required. If the wiring has been badly butchered, then obtain a replacement - and you'll be amazed at how much you worried and sweated and how (conceptually) simple the whole thing is, once you've got it done. Doug

 

[JPSmit]

Are new harnesses braided? Do they come with color coded wire or other identifying methods with
good instructions? As I take things down I realize how poorly color coded many wires are which
has resulted in time consuming tagging with photos.
Will new harnesses with instructions be better such that little mystery is encountered?

Thanks

Not sure what you previous experience is with wiring, but, the British Car Industry between the first and second world war standardized their wiring for cars. So, for instance, Brown is always power unfused, purple is always power fused, green is power - switched and so on. While there will almost certainly be PO bodges, you should, for the most part be able to de-cipher your wire harness with a wiring diagram and a continuity tester.

I am currently working on the wire harness for my Vauxhall - which is more complicated than my Midget - BUT the same colour uses! I got a few photocopies of the wire diagram at 11X17 - I then coloured one with markers. I can honestly say that the more time I spend with it the simpler and "smaller" it gets. What started out as a mass of wire is now a pretty logical harness.

None of this is to dissuade you from buying a new harness - often it just makes sense, but, buying from a reputable dealer you should get the proper colour code - and new or not it is worth your while to figure out the wiring and what goes where. It will make onging maintenance much much easier! (especially knowing black is ground!)

 

[tiiM5]

Thanks for the information, the fabric loom on my harness is worn in places but doesn't present a problem other than visual however wires seem to be covered in fabric of the same color with insulation that doesn't really have color coding.
a few of the wires to the regulator are colored but others seem to be all black insulation. I'll try wiping with some solvent to see if color is revealed. Are color coded diagrams available from Moss etc.?

 

[Rut]

Advance does a good job!
Rut
https://www.advanceautowire.com

 

[drooartz]

I redid the wiring on my first Bugeye shortly after I bought it. The harness that was in it was a bit butchered and there were a number of things that didn't work. I documented the process here:

https://www.drooartz.com/index.php?page=32

On the Bugeye at least the replacement was really easy. Took me a weekend, I could likely do it in a day now.

As for diagrams, it somewhat depends on the year of your car. There are some color ones out there for some years, and the various shop manuals have diagrams as well with the colors marked.