Honda CB750K2 Lights Wiring

[philward]

Hi Guys

The ‘never again buy a bike in bits’ CB750K2 project is nearing completion.  Just awaiting exhausts from Saisei (it was me who put David at Saisei onto SOHC forum by the way after making him aware that Yamiya had exhausts in production) and few bits like rear indicator mounts (anybody got spare set to sell?).
Just done wiring and can’t figure out lighting switch arrangements.  I’ve got a DS CB750 K2 wiring harness, genuine Honda (new) ‘Off/HL’ switch that fits between left hand lever and idiot light and reproduction RH switchgear.
The RH switch gear has a red dot, L and R positions.  Wires out of RH switch is White (low beam?), Blue (high beam?), Black (Live), brown/white (live return to rear light/instruments/etc), Red/Yellow (starter button?), Black (Live to engine cut out?) and black white (return live to coils?).   

When wired into the harness and switched on I have:-
Starter working ok
Sparks at HT leads – none when cut out switch used
Red dot position – no lights
L position – Low beam and parking light
H position – High beam and parking light
Ignition switch parking position – parking light on

The above is achieved either by wiring with ignition live to black or by putting Off/HL switch in series to live.

My problem is why can’t I get the pilot light on on its own? I thought the Off/HL would switch on pilot light in the red dot position then use L and H for low/high beam.

If I wire Off/HL switch as switched live, it seems pointless as the lights are off in red dot position anyway. So switch is pointless!

I only have an early pre K2 genuine Honda manual/wiring diagram which doesn’t show Off/HL switch.

Any help would be much appreciated.

Phil

[Bitsa (Ralph Wright - RIP)]

Hi
Yep same for me but to be honest I dont like the lights on/off switch cant stand surface wiring anyway discarded it so what I have is
Right hand switch off no lights first postion side light and low beam full over high beam.Main switch turn to park both rear and side light on.
Some countries have lights on all the time and repro wiring although very good compared to some of the shit I have worked with not all the right colours are there.Back in 75 I rememeber my k2 with that on/off setup and when first switched rear and front side light came move right h/bar switch dipped then high
Up to you what do you prefer?To be fair side light is as good as a chocolate fireguard who the hell today will see that?They still pull out in front of you with full beam on
Cheers
Bitsa

[philward]

Thanks Bitsa
I remember the same setup. What's your thoughts on what stops parking light (I used to call it 'Pilot' light) coming on independently? In theory, if its the harness, I should be able to wire the switch to put the parking light on in the red dot position feeding via Off/HL switch by picking up from some wire in the harness. So I think it might be the internal switch bridging/wiring on the repo RH switch.
Any wiring Guru's on the forum?!
Phil

[Bitsa (Ralph Wright - RIP)]

PHIL
Same for me re pro r/h switch re pro loom colours don't match I did give 20 Min's or so even the crap winker buzzer colours all wrong I hate re pro crap but in some circumstances you have no choice so thought  can live without that.It all depends on how concourse you will be satisfied with.
cheers
bITSA

[mickwinf]

sounds like you have a mix of uk and us wiring. on my 500 of similar year the separate switch is the on and off, then the rh switch has 3 positions, p (park or side light only) then L low beam and H high beam. The US bikes don't have a sidelight so rh switch has off/l/h positions. not sure if a sidelight is necessary for MOT, Bryan/oddjob/ trigger would know

[philward]

I think your right - I think I got the RH switch from jtmarks in USA. Just started stripping switch but decided not to try re-wiring internal slider as I always ride with dipped beam on anyway - and didn't want to chance wrecking 50 squids worth of switch!
I have an old switch that's knackered but slider could be transferred - when I'm brave enough!
Thanks

[Bryanj]

UK MOT sez you must have side light but it can have dip/head on at same time, if just to get through test connect side light to clock lights.

US red dot is off

[philward]

Sorted! Wired off/HL switch in series to brown lights wire and disconnected brown white from R/H switch. Off/HL now switches side lights/instruments and R/H for low/high beam with off/HL keeping instrument lights on.
Thanks for all your help guys