Honda-SOHC

SOHC.co.uk Forums => CB350/400 => Topic started by: mattsz on January 11, 2019, 09:18:11 PM

Title: CB400F wiring diagram
Post by: mattsz on January 11, 2019, 09:18:11 PM
EDIT (1/17/2019): The UK diagram is available.  Skip the boring build-up:

http://www.sohc.co.uk/index.php/topic,17969.msg156361.html#msg156361 (http://www.sohc.co.uk/index.php/topic,17969.msg156361.html#msg156361)


EDIT (9/16/2019): I added the USA diagram to the same post above.  There have been a couple of questions about it, and I know some USA bikes end up in the UK anyway, so why not?

I've been foxtrotting with a few guys over on the US group about the wiring diagram for my bike, and the potential errors it has - or at least the things about it that confuse me.  In my "spare" time I've been working on creating a color version of it.  I know there's a few around already, but none has quite the detail I'd like to see for the USA models.  What I've done is basically recreated the diagram I found in the copy of the factory service manual that's posted in the "Aladdin's Cave" area of this forum.  Since working with that one, I've found other versions, but I've already invested enough in that one, so that's the one I'm committed to (see the first attached file).

I'm still working out the bugs in my version, but I've included a "small" sample of what it looks like (second attached file) - the full version is a high resolution pdf file, for screen viewing or for printing on (ideally) A3 (US 11" x 17") paper.

I have a similarly laid out UK model diagram; there's some minor differences which most of you know about.  My question is, would anyone be interested in a similar large-format diagram for the UK model?  It wouldn't be too difficult to do - just a question of whether anyone likes this particular layout...
Title: Re: CB400F wiring diagram
Post by: taysidedragon on January 11, 2019, 11:27:01 PM
That's nicely done. I would like to see a UK version.
Nice and clear. 👍
Title: Re: CB400F wiring diagram
Post by: Andych on January 12, 2019, 12:01:08 AM
That is brilliant and really easy to follow.. I would like to see a UK version too.. the Aussie delivered bikes are pretty much the UK version.
Title: Re: CB400F wiring diagram
Post by: mattsz on January 12, 2019, 01:16:15 AM
Twist my arm...  ;)

stay tuned!
Title: Re: CB400F wiring diagram
Post by: SteveD CB500K0 on January 12, 2019, 07:40:38 AM
If you have a hi-res pdf, could I have a copy for Aladdin’s Cave?

Steve


Sent from my iPhone using Tapatalk
Title: Re: CB400F wiring diagram
Post by: mattsz on January 12, 2019, 09:16:39 AM
If you have a hi-res pdf, could I have a copy for Aladdin’s Cave?

Steve

Absolutely!  Once I'm sure I haven't make any mistakes, I'll offer it for general consumption.  Then, hopefully at least one other person will look it over and point out whatever mistakes I was sure I hadn't made but did.  Then we're off to the races...
Title: Re: CB400F wiring diagram
Post by: Laverda Dave on January 12, 2019, 02:40:31 PM
That's excellent work Matt. I second a UK version, a lot easier to read.
Title: Re: CB400F wiring diagram
Post by: mattsz on January 12, 2019, 03:07:54 PM
That's excellent work Matt. I second a UK version, a lot easier to read.

Already in the works...
Title: Re: CB400F wiring diagram
Post by: Orcade-Ian on January 12, 2019, 03:59:15 PM
That’s wonderful work and far easier to fault find with all the colours visible.  One of my 400’s is a very early US spec but I’ve more or less changed stuff for UK.  I know it can be easy to confuse colours on very old wiring so this will help considerably.
As I was writing this, the name Bob Newhart (a US comedian) sprang to mind.  He did a great take about an unexploded bomb and not mixing up wires.

https://m.youtube.com/watch?v=ArMf6xbMsLI

Ian
Title: Re: CB400F wiring diagram
Post by: mattsz on January 13, 2019, 11:55:28 PM
As I was writing this, the name Bob Newhart (a US comedian) sprang to mind.  He did a great take about an unexploded bomb and not mixing up wires.

https://m.youtube.com/watch?v=ArMf6xbMsLI

Ian

I'll give it a listen, Ian, thanks!  I do like Bob Newhart; I see that one goes back aways...
Title: Re: CB400F wiring diagram
Post by: mattsz on January 14, 2019, 12:30:31 AM
What years are represented by the diagrams in these manuals?  My copy of the shop manual says '72 CB350F, and I believe '77 was the last year for this version of the CB400F?  I'd like to know how to label my version...
Title: Re: CB400F wiring diagram
Post by: Sprocket on January 14, 2019, 08:21:52 AM
Good work that man! Having stripped my old main loom last night to prepare to rob bits off it to make the missing rear light loom, I can identify with the Haynes book diagrams being a bit fiddly to read.
Title: Re: CB400F wiring diagram
Post by: mattsz on January 14, 2019, 09:17:01 AM
I'm thinking I'd like to get some feedback about errors before I post anything here in public - anyone willing to look over my "draft" version while I sort out the years in question?
Title: Re: CB400F wiring diagram
Post by: taysidedragon on January 14, 2019, 10:55:36 AM
I'm thinking I'd like to get some feedback about errors before I post anything here in public - anyone willing to look over my "draft" version while I sort out the years in question?

I'm not an expert electrician but I know my way around a wiring diagram. I'll check your draft version for you if it helps. 👍
Title: Re: CB400F wiring diagram
Post by: Bryanj on January 14, 2019, 12:17:46 PM
Email it me direct and i will print it out and compare if you wish.
Title: Re: CB400F wiring diagram
Post by: mattsz on January 14, 2019, 03:03:06 PM
Thanks guys - I'll PM you a dropbox link...
Title: Re: CB400F wiring diagram
Post by: mattsz on January 16, 2019, 10:18:13 AM
I've already had some input about my work; one proper error spotted so far - thank you taysidedragon! - but in my defense, the error was in the source diagram, and I just carried it over!

I've seen enough diagrams with enough variations to know that I'll probably never know what's "correct."  This includes bulb wattages, of which I've seen three different spec discrepancies among various bulbs listed on diagrams all purporting to represent UK models. So I'm just going to add a disclaimer, stating that bulb wattages on some bikes my be different than shown in my diagram... anyone know for sure what the UK bulb wattages should be, or have any other thoughts about this?
Title: Re: CB400F wiring diagram
Post by: Bryanj on January 16, 2019, 10:56:42 AM
Cant remember all of them but some Honda diagrams are marked in cp (candle power).
Indicators 21W
Tail 5/21W
Idiot lights 3 or 4W but had to be a specific shape
Headlamp 35/35 i think
Title: Re: CB400F wiring diagram
Post by: mattsz on January 16, 2019, 11:00:01 AM
Cant remember all of them but some Honda diagrams are marked in cp (candle power).
Indicators 21W
Tail 5/21W
Idiot lights 3 or 4W but had to be a specific shape
Headlamp 35/35 i think

Candle power, huh?  Not sure I've come across that yet...

What's the story with a 35/35 headlamp?  Isn't the high beam meant to be brighter?  Or, do this headlamp's high and low beam simply aim differently?
Title: Re: CB400F wiring diagram
Post by: Bryanj on January 16, 2019, 11:46:51 AM
In Uk the dip beam has aim lower so as not to dazzle oncoming vehicles and cars plus more modern bikes have to have a defined "cut off" pattern that aims left, to the sidewalk,  as well.
Title: Re: CB400F wiring diagram
Post by: mattsz on January 16, 2019, 12:16:37 PM
In Uk the dip beam has aim lower so as not to dazzle oncoming vehicles and cars plus more modern bikes have to have a defined "cut off" pattern that aims left, to the sidewalk,  as well.

Of course - it's the same here, except the light pattern favors the right side.  But the lights I've seen all have a brighter (higher-wattage) filament for the high beam...
Title: Re: CB400F wiring diagram
Post by: Bryanj on January 16, 2019, 12:29:01 PM
A lot do but the 400 has what is best described as a "marginal" charging system and only charges at over 3,000 revs so the less load the better which is the main reason i do not like the US idea of no lights off switch, you are draining the battery as soon as you turn the key.
Title: Re: CB400F wiring diagram
Post by: mattsz on January 17, 2019, 03:52:01 PM
Well, the sooner it goes public, the sooner more errors will be spotted!

Here's my disclaimer...

I think the color scheme is obvious - primary color solid line, secondary color (where used) dashed line overlaid.  Black dots for connection nodes.

I did take a few liberties with the original: almost all of the wire layouts match, with just a few adjustments for where I had to reposition a few components, or for clarity.  I think I went with the UK diagram word choices. Some of the component designs are different, as I used some from a diagram I made for another bike, but I think there won't be any confusion there.

A further note about viewing and printing... I don't have a great printer, and it can only take up to our "standard" letter size paper widths (8.5").  So, it was always my intention to outsource a decent 11"x17" printout.  My local Staples (office supply store) provides an inexpensive (less than a dollar), excellent quality, water-proof ink-jet print on this large size paper - very close, I believe, to your A3 size.  The whole thing should be easily resized to fit on whatever paper size is close (or, just stick with the computer screen!).  You may notice a couple of striped wires shown slightly thicker than others - this, and the color choices themselves, were a compromise to best benefit the appearance and contrast on the computer screen and on this "commercial" printed page.  I hope they're ok if you try to print at home!

It's a PDF file - as for the source document, I've been using a Mac-based program called EazyDraw for a long time, which I think doesn't play very well with other drawing programs.

I'm working on some secondary diagrams which show various systems in isolation; eventually I may make those available as well, as a collection.  Something to pass the time...

I'll attach the file to this post, but just in case, here's a dropbox link to it as well...

https://www.dropbox.com/s/bjm0hcigcjzsfku/1977%20CB400F%20UK%20Master%20Diagram.pdf?dl=0 (https://www.dropbox.com/s/bjm0hcigcjzsfku/1977%20CB400F%20UK%20Master%20Diagram.pdf?dl=0)

PS: Steve, I don't see why you can't drop a copy into Aladdin's Cave - if I discover any changes need to be made, I'll make them and let you know...


EDIT: Just for giggles, I've added the USA version - I know some USA bikes end up over there in the UK, so why not?  There are a few differences!  PDF attached at the bottom of this post, but here's a dropbox link:

https://www.dropbox.com/s/3p9uspbu4u7830y/1977%20CB400F%20USA-Canada%20Master%20Diagram.pdf?dl=0 (https://www.dropbox.com/s/3p9uspbu4u7830y/1977%20CB400F%20USA-Canada%20Master%20Diagram.pdf?dl=0)
Title: Re: CB400F wiring diagram
Post by: taysidedragon on January 18, 2019, 10:37:25 AM
Thanks for producing this Matt. I'm going to print a large copy and it will be my go to wiring diagram from now on. 👍
Title: Re: CB400F wiring diagram
Post by: mattsz on January 18, 2019, 10:38:38 AM
Thanks for producing this Matt. I'm going to print a large copy and it will be my go to wiring diagram from now on. 👍

Thank you for helping me fix it!
Title: Re: CB400F wiring diagram
Post by: Sprocket on January 18, 2019, 11:39:03 AM
You're an absolute star! That's timely for my rebuild! Thank you very much for sharing. 8)
Title: Re: CB400F wiring diagram
Post by: mattsz on January 18, 2019, 11:40:34 AM
You're an absolute star! That's timely for my rebuild! Thank you very much for sharing. 8)

My pleasure - I hope you don't discover any errors the hard way!
Title: Re: CB400F wiring diagram
Post by: Laverda Dave on January 18, 2019, 11:44:18 AM
Thanks Matt for producing this. I'll print it and add to my Haynes Manual. Top work, well done👍
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