Lucas A10 wiring loom

[Spaceman]

The wires mentioned look fine to me comparing diagrams with the only difference being the horn press wire being black rather than black/brown as in the Owner's Manual diagram. In both diagrams, the regulator earth is shown as a black wire.

As said, if you are not worried about having authentic wire colours, it is just a question of making sure the harness fits the bike and has the right connectors in the right places. I'm not sure any of the A10 harnesses being advertised use authentic wire colours!

[Catz]

  well well, which way to turn.     All good ideas though. I'm leaning towards giving it a go or am i 

[idie]

I have never found the wiring looms match the book colours. I just fit to frame and follow where the wire lay. You soon work out which go where.

[EDDIE SIMPSON]

i am not so sure fitting this loom is a good idea. studying the diagram further black must be the earth circuit and red then brown the live circuit. however you have black wires going from t5 supplying live to the rear light and speedo bulb. it should be maroon. then there is a spare brown wire going to the rear light ?. brown is live from the ammeter and battery. are the black wires from t5 a separate circuit from the black wire earth circuit?
when you have a breakdown the colour scheme on this loom will throw you into total confusion when the correct scheme is better because bsa used more coloured wiring.

[DAVE BRADY]

Hi,

Al Osborn, AO Services, will supply a wiring kit complete with correct colours, connectors and self amalgamating tape etc.  A dynamo kit is about £36 including postage.

Dave.

[Spaceman]

The only way you will be able to determine whether this wiring harness is usable or not is by checking it against the OEM wiring diagram - the coloured wiring diagram provided is clearly not 100% accurate! I would be surprised if the harness was not usable!

If you are not able to check the wiring harness in this way then it is probably better to send it back and buy the one recommended with the correct colour coding.

[Spaceman]

Hi,

Al Osborn, AO Services, will supply a wiring kit complete with correct colours, connectors and self amalgamating tape etc.  A dynamo kit is about £36 including postage.

Dave.

On looking at this web site, I think it may not be suitable as they appear to only provide the wiring harness components for the Buyer to construct the loom themselves rather than providing a complete manufactured loom.

I did see the loom being advertised below which looks as though it may have the correct wire colours but you never know until you get your hands on it. On reflection, it may be best to try to use the loom already purchased?

https://www.autosparks.co.uk/bsa-a7-a10-braided-wiring-harness

[DAVE BRADY]

Hi,

Yes, the AO Services kit is exactly that.  I have used on for an A65 and it worked out quite well.  As the wires provided are over length it is then possible to route the harness perhaps better and tidier than with a pre made one.

Dave.

[Catz]

Thanks to everyone for advice. Thanks Dave Brady, i took the other loom back to the shop today and got one for a +ve Earth though it states on the diagram that it's for a 1948 - 54 A7/A10, no swinging arm model. Comparing it to the Haynes and the colours correspond very nearly the same. Confused is the word, and i'll keep the other loom as a standby. Trust Lucas indeed.
WP_20221107_12_36_07_Pro by XJR1200 TIGER, on Flickr

[EDDIE SIMPSON]

that diagram and loom is a lot better.. what bike was the other loom for?
also i would run a earth wire to rear light unit for reliable rear light and brake light.

[Catz]

Hi Eddie, i'm getting you and Dave mixed up, newby-itis going on.
The other loom is for an A10 from 1954-62 swinging arm model and my bike is an A10 swinging arm model from 1960. Something is amiss at Lucas quality control i think.
Thanks for your help.

[DAVE BRADY]

Hi Catz,

I don't mind being mixed up with Eddie. 

Dave.

[chaz]

Im currently rewiring a 1978 Harley xl1000, the loom is burnt in parts and has had wires joined in over the past so one colour going in may be a different one coming out. you are lucky having options for BSA looms, local dealership cant even supply plugs or a battery for the Harley!!

needless to say, Im doing it myself. Ive got a couple of original looms on ebay but dont think they are A10, my a10 plunger was rewired ourselves.