Author Topic: Wiring connectors, what size are Honda?  (Read 904 times)

Offline Laverda Dave

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Wiring connectors, what size are Honda?
« on: August 30, 2025, 11:10:22 PM »
I'm trying to determine exactly what size of wiring connectors are used on the 1976 TL125s I am currently restoring.
Something I thought would be easy to determine is turning out to be a brain teaser!
So far I've come across 2.2, 2.8 and 3.6mm connectors on the internet used for Honda bikes. I thought I should be using 3.6mm and life would be a box of chocolates but the Kojat (not sure if I've spelt that correctly) state 2.8mm are used on older Honda's although it doesn't define what is an old Honda? I consider myself to be 'old' but I'm young compared to some people I know!
How do I measure an existing connector to determine the actual size because they are different diameters at the tip and the crimp?
In addition, I would like to use thinner gauge cable to make new parts of the existing loom but I've read as the system is 6v I should use 1.0mm gauge (same as existing) due to the higher resistance in a 6v circuit?
As you can probably guess electrickary when it comes to automotive applications is not my strongest asset!
Any help/guidance would be helpful in order to avoid the finished bike becoming a mobile bonfire!
« Last Edit: August 30, 2025, 11:14:53 PM by Laverda Dave »
1976 Honda 400/4
1977 Rickman Honda CR750
1999 Honda VFR 800FX
1955 750 Dresda Triton
1978 Moto Morini 350 Sport
1978 Honda CB400/4 'The Flying Banana'
1982 Laverda 120 Jota
2020 Royal Enfield Interceptor 650
1990 Honda VFR400R NC30

Offline TrickyMicky

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Re: Wiring connectors, what size are Honda?
« Reply #1 on: August 31, 2025, 07:57:35 AM »
Don't be tempted with thnner gauge cable. Remember the old equation, volts x amps = watts. So, if you use a 30watt headlamp bulb using 6 volts, then it will be drawing 5 amps. One of the main reasons for using a 12 volt system.  I am not genned up on electrickery either, so I was pleased to be taught, only this year, that on lower voltage systems, (up to about 30 or 40),  only use braided cable and not single strand. Apparently, current will follow the path with the least resistance, which is the surface of the cable, not through the central core. So braided cable with a host of strands offers the least resistance.I don't know much about the TL125, but I think on some of the earlier Hondas, it was not too much of a job to convert them to 12 volt. Have fun. Mike.

Offline neat street

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Re: Wiring connectors, what size are Honda?
« Reply #2 on: August 31, 2025, 08:25:46 AM »
Contact Big Al on here, he will do the right connectors for you, at least then you know you have the right size.
CB500 1975
CB750F 1976
KLX250 1983
Lambretta SX200 1979
Mini Mayfair 1984

Offline McCabe-Thiele (Ted)

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Re: Wiring connectors, what size are Honda?
« Reply #3 on: August 31, 2025, 09:05:13 AM »
If you have an original bullet connector I would have thought you could put some calipers on it Dave?

Clearly not 🤐
Honda CB400NA Superdream (current money puddle)
Honda CB500 K1 (second money pit)
https://www.sohc.co.uk/index.php/topic,28541.0.html
Honda CB400 four super sport (first money pit)
Link to my full restoration http://www.sohc.co.uk/index.php/topic,23291.0.html
This is a neat 500 restoration in the USA.
http://forums.sohc4.net/index.php/topic,151576.msg1731556.html#msg1731556

Offline Bryanj

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Re: Wiring connectors, what size are Honda?
« Reply #4 on: August 31, 2025, 09:14:46 AM »
76 is not classed as early, before the 750(1909) some are smaller and as said NO to smaller cable, half the volts doubles the current so bigger xable

Offline SteveD CB500K0

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Re: Wiring connectors, what size are Honda?
« Reply #5 on: August 31, 2025, 11:54:43 AM »
The surface effect only works on AC circuits and then only very high frequency AC. So on DC and normal household wiring the effect is minimal.

Multicore wire is more flexible though so that’s the reason to use it.


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Offline BigAl (Alan)

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Re: Wiring connectors, what size are Honda?
« Reply #6 on: August 31, 2025, 01:00:42 PM »
The electrical connectors on the 1970's models would have had 3.9mm bullet & socket connectors & possibly 6.3mm latched block connectors (for additional lighting)
The early 1980's models where fitted with 2.8mm latched block connectors.
Cable size 1.00mm...nothing smaller
Current bikes:-
Honda CB750 K4 (1974) USA
Honda XL500S (1980) UK
Honda CD175 sloper (1968) UK
Honda CB1100A (2013) UK
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Offline mickwinf

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Re: Wiring connectors, what size are Honda?
« Reply #7 on: August 31, 2025, 10:16:22 PM »
I beg to differ from big al but most 70s honda used 3.5 mm and 3.9 don't always connect with original looms.
Love the 500 and 550 have a 500 called Lazarus under restoration

Offline Laverda Dave

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Re: Wiring connectors, what size are Honda?
« Reply #8 on: August 31, 2025, 10:32:56 PM »
Thank you all for the responses.
I did ask BigAl previously if he made looms for the TL125 but unfortunately he doesn't but he did give me a helpful tip to use Vehicle Wiring Products to buy the connectors. I have just placed the order for £50 worth of cable and connectors. Shame they dont stock the rubber boots used to cover the multiple connectors of the loom around the headstock area (normally sitiing under the fuel tank.
I hope they are 3.9 and not 3.5 othherwise I'll be sending them back!
Hopefully I'll begin modifying the loom this week.
1976 Honda 400/4
1977 Rickman Honda CR750
1999 Honda VFR 800FX
1955 750 Dresda Triton
1978 Moto Morini 350 Sport
1978 Honda CB400/4 'The Flying Banana'
1982 Laverda 120 Jota
2020 Royal Enfield Interceptor 650
1990 Honda VFR400R NC30

Offline mickwinf

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Re: Wiring connectors, what size are Honda?
« Reply #9 on: September 01, 2025, 08:15:44 AM »
If you are replacing both male an female connectors together then no problem.
Love the 500 and 550 have a 500 called Lazarus under restoration

Offline BigAl (Alan)

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Re: Wiring connectors, what size are Honda?
« Reply #10 on: September 01, 2025, 12:02:20 PM »
Pity no one stocks the connector boots (black dip-moulded pvc covers) they are expensive to have manufactured
Please Note - Vehicle wiring products do not stock the replica OE latched 6.3mm connectors for classic Honda's
Current bikes:-
Honda CB750 K4 (1974) USA
Honda XL500S (1980) UK
Honda CD175 sloper (1968) UK
Honda CB1100A (2013) UK
www.alans-electrics.co.uk

Offline Laverda Dave

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Re: Wiring connectors, what size are Honda?
« Reply #11 on: September 01, 2025, 07:08:11 PM »
That's similar to what I am after Al except the one I want is the round one to go over the loom at the bullet connectors (similar to the 400/4). I need 15mm diameter at one end and 40mmat the other.
1976 Honda 400/4
1977 Rickman Honda CR750
1999 Honda VFR 800FX
1955 750 Dresda Triton
1978 Moto Morini 350 Sport
1978 Honda CB400/4 'The Flying Banana'
1982 Laverda 120 Jota
2020 Royal Enfield Interceptor 650
1990 Honda VFR400R NC30

Offline BigAl (Alan)

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Re: Wiring connectors, what size are Honda?
« Reply #12 on: September 01, 2025, 08:27:32 PM »
Image attached, the LHS cover is 20mm @ the top & 50mm @ the bottom
RHS cover is 12mm @ the top & 32mm @ the bottom
Current bikes:-
Honda CB750 K4 (1974) USA
Honda XL500S (1980) UK
Honda CD175 sloper (1968) UK
Honda CB1100A (2013) UK
www.alans-electrics.co.uk

Offline Laverda Dave

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Re: Wiring connectors, what size are Honda?
« Reply #13 on: September 01, 2025, 11:01:52 PM »
That's what I need Al🙂. Do you sell these, I'll take one of each please if you do👍
1976 Honda 400/4
1977 Rickman Honda CR750
1999 Honda VFR 800FX
1955 750 Dresda Triton
1978 Moto Morini 350 Sport
1978 Honda CB400/4 'The Flying Banana'
1982 Laverda 120 Jota
2020 Royal Enfield Interceptor 650
1990 Honda VFR400R NC30

Offline BigAl (Alan)

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Re: Wiring connectors, what size are Honda?
« Reply #14 on: September 02, 2025, 09:38:35 AM »
Just send a PM, I can then  let you know the cost & PayPal details
Current bikes:-
Honda CB750 K4 (1974) USA
Honda XL500S (1980) UK
Honda CD175 sloper (1968) UK
Honda CB1100A (2013) UK
www.alans-electrics.co.uk

 

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