More Wiring questions

[Lynx]

Hi all,

Three questions today.

I wondered if anyone could identify what these two wires are for coming out of the loom near the horn. I am presuming they are not for the horn and one is the wrong colour. One is black and one green with a yellow stripe. I don't actually have a working horn to test that. Picture attached.

Secondly there is a horizontal mounting bracket the other side of the frame to the horn mount. Is anything supposed to be on there on a 1976 UK bike? Picture attached.

Thirdly I have some spare wires  . Coming off the loom into the main collection under the tank I have two female connectors with nothing connected a Light Blue with a White stripe and an Orange with a White stripe. In the headlight shell I have the same two spare coloured wires and a third one Green with a Red stripe.

All ideas greatfully received.

Cheers
Steve

[Lobo]

Hi Steve,

First up, I've been wrong before on these bloody Honda wiring diagrams... seems different countries (can) have different colouring codes / connections.  But here goes...

(1). The Green/Yellow & Black connectors are to the front brake pressure switch under the headlamp.  Touch them together & the rear brake light should come on (with ignition on)

(2) I too am puzzled by this 'bracket'... I genuinely don't think it had a purpose on the UK 400F... certainly I've never seen any picture of it used, despite much searching in a big effort to get my 400F right.

(3) I too have these spare wires; on the American bikes (wiring diagrams) those colours appear to be used for the 'running lights'... you know, they have the orange indicators on all the time, and then also flash for turning. In other words, on a UK Spec machine these wires are superfluous.

Hope this helps,
Simon.

[Lynx]

Thanks for the reply Simon. That's not too bad then, accept I don't have the brake pressure switch.! The brake hoses on my bike have been replaced with a single braided steel hose. Does that mean this switch will have been removed?

On a side line, I tried to start the bike for the first time today  . It fires up but only running on three cylinders  . No.2 down pipe stone cold. There does seem to be a spark on the plug although it's strength seems to vary. I will investigate more a bit later.

Cheers
Steve.

[Lobo]

Hi Steve,

Yep, it sounds like your front brake pressure switch is missing...  Dunno, but would the bike pass a MOT without a working front brake switch? (part #233)

(Ignore the blue boxes... just my method of tracking the bits I've renewed on my bike)

Good stuff on the first start, hopefully something small on #2 cylinder.

Simon


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[tom400f]

I can confirm Simon's colours for the pressure switch connectors.

Standard brake hose setup has a union in it linking top/bottom hoses and a thread for the pressure switch. Pic here:
http://www.sohc.co.uk/index.php?topic=5325.msg26023#msg26023
(the union that is, the pressure switch is at the top-right of that union as you look there and facing away from you. You can just see the back of the hexagon)

[Bryanj]

As long as the rear brake light switch works it should pass an MOT, if you want a front one as well you can get a banjo bolt with a built in pressure switch

[Lynx]

Thanks for that. I think I'll leave it as it is to keep it neat. Interesting about the Banjo with a built in pressure switch though. I didn't know about them and will look into that if I need to. At least I know not to worry about the spare wires. It would have been interesting if I did connect the horn there  .

[tom400f]

you can get a banjo bolt with a built in pressure switch

I thought I saw one on Andrew's (ashewan) 400F - may be mistaken but perhaps he can post a pic if I got  that right...

[ka-ja]

Hi,
     the basics (but not always) of motorcycle lights in an MOT test is that if a lighting circuit  is fitted, it should work, my old honda passed several tests with no rear brake light, but there was no switch for it either, but did have a front switch that worked, there is always a hand signal, not that I encourage one or two finger salute!

[Bryanj]

On the MOT there has to be a brake light but it does not have to be on both brakes, you are correct in that if fitted it must work

[Lobo]

From an MOT UK (Motorcycles & Sidecars) Testers Manual...

Machines first used before 1 April 1986 must have a stop lamp that operates from at least one brake control.

Machines first used on or after 1 April 1986 must have a stop lamp that operates from both brake controls.
However, a small number of machines first used from this date were approved with the stop lamp operated by only one control. A machine should only be failed if you are certain that it was originally manufactured to operate from both controls

On machines without a battery or with an insufficiently charged battery, it will be necessary to run the engine.

[Bryanj]

Lobo, thanks for that, that rule has come in since i stopped testing so good to know