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Swap out Electrical Harness

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J

JBlubaugh

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Hi All-

The last thing I need to do is swap out my 55 year old wiring. Besides all of the splices and PO modifications, it's just getting to the point it isn't safe. I have ordered all new wiring from British Wiring and was curious if anyone has some suggestions or tips to tackle this. I can take something with 50 parts and no diagram, tear it apart, and put it together again no problem but Electrical always seems like voodoo to me.


Thanks,
Jim
 
You do have photos of generally how it's routed, right? Lay the new harness out on the floor generally how it's routed. There's not so many places where the Healey harness connects. Key items to help are:

  • The eight connections that go to the flasher relay
  • The five green wires that connect to the fuse box
  • The heavy wires that connect to the generator control box
  • The mass of wires that connect to the dash

Once you have it laid out, you can tell which part is the heavy part that goes through the 2" (or so) hole in the firewall. That's where you start; by putting the big grommet on the harness, putting what's inside the engine bay in the engine bay and what's behind the dash behind the dash and getting that big grommet in place. Then lay it out one leg at a time. The wires are color coded. Get a wiring diagram and attach the wires to the connection points, which are also labeled.
 
HealeyRick said:
If the old harness still has its wiring colors visible cut off the wires leaving a short piece of wire at each connection. You can then remove one wire at a time and replace it with the one from the new harness
Click to expand...

YEP::applause:
That is just what I always do TOO.:encouragement:

OH I am also from the ole school N i solder all the connectors to their wires.:highly_amused:
 
Last edited:
The only places you can't reach with the engine in--at least I couldn't--are the P-clips that hold the branch going through the transmission tunnel. I cut the old wire out and tie-wrapped the new wiring to the P-clips until I pulled the engine. Rick's advice is spot on, but it helps to have a schematic if you can find one (someone had them a while ago).
 
If your a visually impaired old fart like me Get on e-bay and find a large color laminated version of the wiring diagram for your car . The ones in the manual suck for visually impaired old farts like me .
Follow the colour code and your good to go .
Word of Caution. DO NOT GET THE POLARITY WRONG ON THE REAR LICENCE PLATE LIGHT OR YOU WILL BE BUYING ANOTHER HARNESS !!!!!!!

just looked on e-bay . Every model available less than 20$
 
Two more things:

1) Recommend putting dielectric/silicone grease in all the connectors before you connect them. I believe the atrocious--and not entirely undeserved--reputation of Lucas electrics is partly due to corrosion on the connectors. Dielectric grease--or conductive grease if you prefer--helps occlude air and should diminish corrosion, the cause of many electrical gremlins.
2) This tool is pricey, but you'll be glad you have it ('trust me'): https://www.britishwiring.com/Tool-Snap-Connector-Tool-p/ssc1.htm

It's difficult to ensure you've made proper connections with the old-style bullet connectors and, without the tool, your fingers will be raw by the time you've finished. Too late now, unless you bought the tool, but you could have ordered it with the harness (only a relatively small incremental expense). If they don't, the BW guys should recommend it for someone doing a complete rewire.
 
Would it work to make a connector tool using a cheap pair of pliers. Just slice a slot in the ends.

I took many pictures of my wiring harness before I removed it, and then again with it laying on the floor with large notes attached. It helped. It also helps to have pictures of other cars, assuming they installed correctly.

Dale
 
Hi Jim,

When totally redoing my Healey in the mid 1980, one of the things I did wassend my harness out to be recovered with the proper weave rap. When itwas returned, many of the original ends were returned in a bag, as I hadrequested, and many were corroded. Thebullets had their wire inserted and folded over through the small whole in theend and were lodged in the appropruate connector. And that’s what I received.

When initially booking the harness rapping service, I questioned ifthey had a “Harness Diagram” (not a wiring schematic) that identifiedeach wire, connector, and where it was attached. Insecure withproviding this harness diagram, I finally got them to sell me a copy for all myharnesses and it proved a invaluable and a greate complement to my schematicduring installation.

When installing the harnesses, I made sure each appropriate connector(including each bullet) was soldered onto its designated wire and did not relieupon pressure to secure the connector. Where again appropriate, eachnon-bullet connector was further insulated with heat shrink tubing over thefull length of the receiving connector and extending over onto the wireinsullation. After cleaning and before inserting each connectoronto its receiver (including bullets into their connectors), Iliberally applied Dielectric Grease as the final electrical isolatorand to eliminate any vapor penetration/corrosion. Itshould be understood that Dielectric grease is not conductive butinsersion pressure will easily move the grease aside to expose a goodconnection. Over the years, I have hadoccasion to disconnect both bullet and non-bullet connectors and have not foundany that exhibit corrosion.

Most new harnesses are constructed with heavier gauge wire to carry the load ofmodern electrical additions. Although this improvement does provide a greatermargin of electrical safety, it also can cause more difficulty when fitting theharness into the car. Since my harnesses were, and still are, original,they were not as resistant to meeting the contours when placed. However, to deminish the original and newloads passing through original components and switches, I have supplimented myoriginal wiring with added harnesses constructed with heavier wire and relaysto allow my original components and finer wiring to carry the much loweramperage needed to switch and not operate. In this way, I have added such additions as Halogin head lights,alternator, sound system, etc., and have significantly lowered the level ofpower passing through my old original components and harnesses. Additionaly, these added supplimentalharnesses can actually be removed with components return to originality.

Last, consideradding additional fuses as part of your new harness installation. I chose to add in-line fuses as they areeasily hidden and can be easily installed to cover specific circuits and/orcomponents. How ever you choose to go,it is the perfect time to address adding protection to your electrical system.

Good luck andenjoy the task,
Ray(64BJ8P1)
 
If your a visually impaired old fart like me Get on e-bay and find a large color laminated version of the wiring diagram for your car . The ones in the manual suck for visually impaired old farts like me .

Healey Nut:

Have you tried a good set of Blended glasses ??????

OR maybe you only have an a stigma problem NEED A good optomolgist for this one.
 
Thanks for all the suggestions.

I'll be going with the soldered connectors. I have a couple different versions of enlarged wiring diagrams, including the color version on the internet. My plan is to start in the rear and work my way forward, replacing wires with new harness wires as I go. I'll clip the old harness off as I go leaving some of the old wiring in place so I can match colors if able.

What about laying the new harness out and labeling leads with a continuity tester? Would that be beneficial or more hassle then it is worth?

Thanks,
Jim
 
Bob Spidell and Healeynut give good advice. When I restored my 100 the new harness was one of the first reassembly jobs. At first I thought I had bitten of more than I could chew! But once I started it went well, in fact that was one of the most enjoyable aspects of the restoration, especially when I powered it up and everything worked.
I have just done the rewire on a Sprite. That was a challenge because the diagram in the workshop manual is schematic. Like Healeynut I located a colour diagram on the Internet that showed the wires as thay are laid out in the car, just as the 100 manual does. It was free too! Good luck.
 
JBlubaugh said:
Thanks for all the suggestions.

I'll be going with the soldered connectors. I have a couple different versions of enlarged wiring diagrams, including the color version on the internet. My plan is to start in the rear and work my way forward, replacing wires with new harness wires as I go. I'll clip the old harness off as I go leaving some of the old wiring in place so I can match colors if able.

What about laying the new harness out and labeling leads with a continuity tester? Would that be beneficial or more hassle then it is worth?

Thanks,
Jim
Click to expand...
Hi Jim
continuity tester ca be sobstitued by a simple 12v lamp and adeguate wires and clamps, one IMPORTANT suggestion is avoid the BATTERY connection use- one
little 12 V supplier with 5-10A capacity and automatic protection -(one little battery charger, the orange one in the photos where you can see also the lamp probe), this assure that if a short occour your harness NOT burn withouth you have the time of disconect the battery
https://picasaweb.google.com/112770...ATIONAUSTINHEALEY10061958#5413650978214417682
I have proceded in different way (rebuilding completly a 100/6 with a NOT original rewiring) labelling each wire -and testing the harness on table
BUT car was completly dismantled- some photos up and down on this album can help you .-- use the lateral arrows
I don't know what AH model you use also this 3 album can help you
https://picasaweb.google.com/112770819864514987162/SCHEMAImproved1006
https://picasaweb.google.com/112770...LEY10061958BeginningMayJune2011endMayJune2013
A crazy album, but useful photos
https://picasaweb.google.com/112770819864514987162/DropBox
 
JBlubaugh said:
I'll be going with the soldered connectors.
Click to expand...

Just as an aside, I used to subscribe to an ad-free--they could tell the truth or give a controversial opinion without upsetting advertisers, but the subscription cost was significant--magazine about aircraft mechanics (forget the name, maybe 'Aircraft Mechanics?'). They investigated which is the proper way to affix connectors to wires (electrical wiring is arguably more critical in an airplane). Surprising to me, they recommended crimp connections over soldering. As I recall, with soldering you risk 'cold solder,' and solder would eventually corrode in that environment and, of course, crimping is quicker and easier. If you check your new harness I think you'll find the connectors are crimped. I bought the crimper tool from British Wiring and an assortment of connectors for different wire gauges; it works a treat. Turns out, most if not all connectors in a Healey harness are one size, so the rest I bought are essentially wasted. Though expensive, the crimper is worth it IMO (no way to make one from a pair of pliers). When I wired our BN2/100M I pulled at least one connector off the wires--so be careful of that--but had the crimper and connector handy. Guess you could say that's an argument against crimping and, done properly soldering may be preferable, but with soldering you really have to be sure the solder flows properly and to get the connector hot enough you risk damaging the wrap. Be sure to 'tin' the wire before soldering.

As a double aside, we bought a used but apparently good fuel tank for the BN2 from one of the credible suppliers ($400!). We had problems with erratic fuel delivery; went through pump, lines and carburettors. Finally, my dad deduced it had to be a problem with the tank and I don't know how he figured it out but there was a small hole in the pick-up tube near where it was soldered to the tank and severe corrosion all around the area; the rest of the tank was in good nick. Dad figured the flux they used to solder the tube to the tank caused corrosion which eventually ate through the tube. That would almost certainly have been an acid flux; with wiring you would use rosin core/flux solder.
 
with wiring you would use rosin core/flux solder.

YEP-Bob- N:;

The Aircraft wiring that is crimped is done with an expensive machine and then PULL tested to a specification with another expensive machine prior to delivery.

Even a home crimping tool that is reliable is expensive.

Soldering is just another capability that can be acquired
 
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