Author Topic: Attention Wire Gurus CB750K8  (Read 2810 times)

0 Members and 1 Guest are viewing this topic.

Offline tinyrobot

  • Hot Shot
  • ***
  • Posts: 276
  • Mock it up before you Fock it up!
    • ChiVinMoto
Attention Wire Gurus CB750K8
« on: March 27, 2008, 01:44:53 PM »
During my "Race Inspired" look for my 78 CB750 I have decided to lose the turn signals, flasher, buzzer, Left Hand Controls, Front Brake Switch, and the Speedometer.  Before ripping everything off joining some wires and praying to the beer gods it fires up, I thought I would mod the wire diagrams to reflect my changes before I even drop the first turn signal.

Can some of you Electrical/Wire gurus review these for me and if they are correct, maybe others can uses them from the FAQ section.

Took about 5 min in windows paint and some review of Honda Mans active wire diagrams.

Let me know how I did and what I probably screwed up.

Stock


No Aux w/ Stock Head lamp


No Aux w/ Single H4 Lamp

Offline mustangcar

  • Enthusiast
  • **
  • Posts: 194
Re: Attention Wire Gurus CB750K8
« Reply #1 on: March 27, 2008, 02:33:12 PM »
wish i could help you but it looks like a bunch of colored spegetti to me,iam going to try to wire  my k8 all up the way choppers do it start from scratch,there is some diagrams on slickchoppers.com,wish i was in that wiring stage now still far from it,,sand blasted the frame and also just finished painting the tank ,now i decided to polish the whole engine cases,oh boy am i asking for work,,,i rigged up a test harness to work with my original turn signal switch,just remember the hot +wire first goes to the flasher itself then to the handlebar turn switch ,the turn signal lights are already grounded to the frame,the switch just completes the circuit
« Last Edit: March 27, 2008, 02:34:44 PM by mustangcar »

Offline TwoTired

  • Really Old Timer ...
  • *******
  • Posts: 21,805
Re: Attention Wire Gurus CB750K8
« Reply #2 on: March 27, 2008, 06:03:33 PM »
Looks like they will work.  The diode was there to keep the neutral light off when the clutch was pulled.  Since you eliminated the clutch switch, you no longer need the diode.

Cheers,
Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

Those that learn from history are doomed to repeat it by those that don't learn from history.

Offline tinyrobot

  • Hot Shot
  • ***
  • Posts: 276
  • Mock it up before you Fock it up!
    • ChiVinMoto
Re: Attention Wire Gurus CB750K8
« Reply #3 on: March 28, 2008, 07:16:25 AM »
Thanks guys, I will post some updates later on with my progress.

Offline tinyrobot

  • Hot Shot
  • ***
  • Posts: 276
  • Mock it up before you Fock it up!
    • ChiVinMoto
Re: Attention Wire Gurus CB750K8
« Reply #4 on: April 22, 2008, 05:35:11 PM »
Well I have the harness off and slimmed down to what I want as far as auxiliaries go.  I am going to try and replace the start/stop control and use a quick turn throttle with this new starter control I got:



Problem is the wiring is a bit different I have just about lost my mind on this one.  Any help would be greatly appreciated.  Here is the new start button diagram:
http://www.redracingparts.com/pictures/s/sch0038AB00.gif

I guess I'll try a flat out what goes where and see what I can get from you guys?

arttbags

  • Guest
Re: Attention Wire Gurus CB750K8
« Reply #5 on: April 22, 2008, 05:55:26 PM »
Good luck I'll be watching for updates. I'm attempting a similar project my 78k's wire harness was all hacked up. I'm having trouble finding anything that matches my harness colors.I'm keeping the speedo too but only rear turns and I'm on the look out for better bar switches if any one can point me in the right direction..

Offline TwoTired

  • Really Old Timer ...
  • *******
  • Posts: 21,805
Re: Attention Wire Gurus CB750K8
« Reply #6 on: April 22, 2008, 08:48:38 PM »
You have two switches in the control.  What do you want them to do?
Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

Those that learn from history are doomed to repeat it by those that don't learn from history.

arttbags

  • Guest
Re: Attention Wire Gurus CB750K8
« Reply #7 on: April 22, 2008, 11:40:49 PM »
I'd like to replace them all with something sleeker, less bulky look.

Offline tinyrobot

  • Hot Shot
  • ***
  • Posts: 276
  • Mock it up before you Fock it up!
    • ChiVinMoto
Re: Attention Wire Gurus CB750K8
« Reply #8 on: April 23, 2008, 01:09:20 PM »
You have two switches in the control.  What do you want them to do?

The red button is a two position in (off)/out(run) that I would like the kill switch to be.  The black in a spring button that I would like to power the electric start.

Offline tinyrobot

  • Hot Shot
  • ***
  • Posts: 276
  • Mock it up before you Fock it up!
    • ChiVinMoto
Re: Attention Wire Gurus CB750K8
« Reply #9 on: April 23, 2008, 01:10:19 PM »
I should mention that I can solder and will buy the correct plugs to make this work similar to stock.

Offline TwoTired

  • Really Old Timer ...
  • *******
  • Posts: 21,805
Re: Attention Wire Gurus CB750K8
« Reply #10 on: April 23, 2008, 06:01:50 PM »
The black starter button has a black/White and an Orange.
Attach these to Black and Yellow/Red in your wire harness.

You new switch has no provision for the headlight interrupter.  So, to get your headlight back, connect the Black/Red to Black in the harness.  You can expect the bike to be a bit harder to start, as the headlight will suck the battery voltage lower during starting.

The red button has three wires to it.  And the schematic doesn't seem to use standard electrical notation, so here is a guess.
Assuming it is a momentary switch and doesn't lock into position like the stock one does, connect the black switch wire to a black wire in the harness.
Connect the Blue switch wire to the Black/White wire in the harness.

I *think* the Black/Yellow wire is only connected to the blue when the button is pressed.  If I'm right, this wire should remain unconnected and is probably best insulated from any connection.

That's my best guess with the info provided.

Cheers,
Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

Those that learn from history are doomed to repeat it by those that don't learn from history.

Offline Bodi

  • Really Old Timer ...
  • *******
  • Posts: 5,697
Re: Attention Wire Gurus CB750K8
« Reply #11 on: April 23, 2008, 06:41:59 PM »
According to the website actual catalog page (redracingparts.com) this has a start switch and an engine kill switch - the big red one is probably the kill switch. The electrical symbols used on the "schematic" are totally confusing, and looking at the assorted other switches doesn't help... individual start and kill switches have the same zap-in-a-circle symbol... and neither has the SPDT arrangement shown in this unit.
I think the start switch uses SPST NO switch on the black/white and orange wires. The kill switch is odd, in one position it connects blue to black, in the other it connects blue to theblack/yellow wire that is separate from the modular connector and has a bullet connector. This should be a toggle switch, usually you pull it up to run so that in an emergency you just have to whack at it to push the button down and stop the engine. Possibly they give you this wiring scheme because some ignitions (like ours for example) would switch off the coil power to kill the engine using the pair connected when the button is up, and some ignitions (magneto for example) connect a wire to ground to kill the engine using the pair connected when the button is down. With this switch on a SOHC4 ignition you could easily install a warning light to show you when the kill switch is engagel - that would have saved me a sore leg on several occasions!
These are guesses, so don't just assume I'm right!
Check the switches and wires with a meter. Whatever wires are connected only when the start switch is pressed should go to the starter. If the starter is actually the SPDT switch, you can preserve the headlight kill function.