Mystery Plug - Can you Identify?

[jbeach]

Dear Wiring Experts,

I am still rewiring my '69 S4 DHC. I have come upon a mystery that is not addressed in the wiring diagram I am using (an excellent color diagram I downloaded from this website).

I am replacing my original, fully-bodged, wiring with crisp, clean wiring harnesses from British Wiring. Unfortunately, I am unable to identify a bunch of stuff, including this plug:

As you can see, it emerges from the wiring loom in the compartment in front of the radiator. I am not finding a male analogue and do not see where these wires appear in this area on my wiring diagram.

Many thanks!

-John

[nmauduit]

Alternator plug, and thick brown are the charging wires (possibly fiting a Lucas ACR 17 I would say, it looks quite similar to what I recall I had to source to fit one)

[Baggy2]

Yep - plugs in the back of the alternator

[jbeach]

Perfect! Thank you, that solves two mysteries.

I do wish someone would direct me to a color wiring diagram using an alternator. While the ones I found on this website are excellent, they all show a dynamo, which I assume is the British term for a generator.

A continuing “thank you” for everyone’s help!

-John

[nmauduit]

I do wish someone would direct me to a color wiring diagram using an alternator. While the ones I found on this website are excellent, they all show a dynamo, which I assume is the British term for a generator.

the wiring of the alternator itself should not be difficult, as it contains its own regulator (as a proof, I don't recall much of it when retrofiting one on my 1968 S4se... or what is it a proof of?):
- the thick solid brown is the main charge wire, and should end up to the battery positive at the starter solenoid
- the thin brown/yellow is the dash light
- then second, thin solid brown... I believe it should also be connected to the battery positive (doing a retrofit on a dynamo harness, and willing to keep the RB106 dynamo regulator for looks and reversibility, I did that on the terminal A of said regulator, which was partially disconnected to act as a terminal box)

there are some colored wiring diagrams on https://lotuselan.net/forums/viewtopic.php?f=38&t=30750 , though not including the alternator mod I believe...

solid brown is usually the main battery feed in Lucas color code
https://www.jcna.com/lucas-wiring-colors-0

[RichardS]

Perfect! Thank you, that solves two mysteries.

I do wish someone would direct me to a color wiring diagram using an alternator. While the ones I found on this website are excellent, they all show a dynamo, which I assume is the British term for a generator.

A continuing “thank you” for everyone’s help!

-John

There are some wiring diagrams on this site
Go to Wiki Coming Soon at top of Home Page. Click on Shop Floor, Workshop Manual, Electrical and there you are!
Richard