cb750 k4 wiring help, I'm desperate

[nightpoison]

Ok, so I've done a bunch of research and have come across several articles that have helped me out, but I'm still not 100%, not that close either. Here’s the back story real fast. Picked up a CB750k4 with some wiring issues. Left hand controls (LHC) didn't work and the tach lights were dead. So I did some shopping and found some new equipment, LHC RHC Tach, Speedo. Indicator lights are now integrated with the DCC Speedo. The wiring harness was such a mess I ordered a new one from vintagecb750.com.

I wired up the bike and had four extra wires. well it seems that the new harnesses are a mixture of the UK and US bikes, so I need to bridge the brown and black wire that was left over and the brown/white with the brown/red that were left over. When I did that I got tack and speedo back lights lighting up, and then the brake light started to work as well. The Headlight would turn on only when I had the High Beam on.

So I took everything apart and I'm now starting over. The first time I made some educated guesses. This time I'm hoping I can make some informed choices.

the issues: no running lights at all, turn signals won't work at all, no low beam(running lights again, I think), starter/kill switch, and horn. So I've created a list of questions that I'm hoping I can get some help with.

1) Motion Pro start stop switch. (See attached photo of wiring diagram for right hand control)
A) ON/OFF SWITCH: does it matter which wires I connect this too? The motion pro has a black and blue/black. right now I'm running the black with the black/white on the harness & the blue/black to the black wire on the harness.
B) STARTER: there are two sets of wires that work the starter switch. for my bike I believe I only use one set of these. do I use the white & yellow or the gray & red/black combination? and which of those would I connect to the yellow/red & green/red wires to operate the starter?

2) Left hand controls.
A) Head light: so the headlight plug has three lines. Black (ground) Red (drive) green (pass). I came across another post where they said that the Black is ground, red is low beam, and green high beam. So I connected the red wire directly to the LHCs to the yellow low beam wire, and the green wire to the green High beam wire along with the Positive wire for the High beam indicator light. HL main wire from the LHC is Red and I’m connecting it to the Brown/red wire on the harness. the HB LED ground I'm running to a green ground.

B) turn signals: so I have dual filament signals for both front and back. the back I'm only using the ground wire and the flasher (positive) wire. as there are only single filament connections for the rear I just left it that way. Should I order a single filament or is this fine?

for the front. the red is the flasher (positive) wire which I connect to Orange (left) & light blue (right) on the harness. I also connect the LTS wire (brown) from the LHC to the orange harness wire & I connect the RTS wire (dark green) from the LHC to the light blue harness wire.

the Black/white wire is the ground which I run to the green harness wire for both the LT and RT front signals.

The last wire is black which is labeled as running light, which I run to the orange/white (left) & the light blue/white (right) on the harness. I don't connect anything else to the orange/white or light blue/white

Main turn signal wire on the LHC I run to the brown/white wire on the harness

is this correct?

C) Horn LHC pink wire connects to light green signal harness wire, and the horn ground from LHC (black) I connect to the black harness wire

correct?

sorry this is such a long desperate post. I was hoping to have the bike on the road last week.

 

[nightpoison]

anyone know a shop on the North shore of Boston I can take it too? I'm having no luck with it, so I might just need to take it in for someone else to get it up and running for me.

 

[Sonreir]

Right hand control, from control to harness:
Green - black
Green - green/yellow (doesn't matter which green goes to which wire)
Black - black
Blue/black - black/white
Gray - black
Red/black - red wire on left control
White - green
Yellow - yellow/red

Left hand control, from control to harness:
Yellow - white from headlight
Black - green
Brown - orange
Green - blue wire from headlight
Brown/white - gray
Red - Red/black wire on right control
Blue - green
Pink - light green
Dark green - light blue

 

[nightpoison]

Right hand control, from control to harness:
Green - black
Green - green/yellow (doesn't matter which green goes to which wire)
Black - black
Blue/black - black/white
Gray - black
Red/black - red wire on left control
White - green
Yellow - yellow/red

Left hand control, from control to harness:
Yellow - white from headlight
Black - green
Brown - orange
Green - blue wire from headlight
Brown/white - gray
Red - Red/black wire on right control
Blue - green
Pink - light green
Dark green - light blue

Sonreir,

Wow thanks. I cant do it today but hopefully tomorrow ill spend some time getting every th ing hooked back up.

 

[nightpoison]

thank you for the help. I got outside to work on the bike today, low beam is up and running, the starter is kicking over, all the lights for indicators are now working. I'm still not getting any turn signals.

could that be an issue with the dual vs single filament in the back?

Right hand control, from control to harness:
Green - black
Green - green/yellow (doesn't matter which green goes to which wire)
Black - black
Blue/black - black/white
Gray - black
Red/black - red wire on left control
White - green
Yellow - yellow/red

Left hand control, from control to harness:
Yellow - white from headlight
Black - green
Brown - orange
Green - blue wire from headlight
Brown/white - gray
Red - Red/black wire on right control
Blue - green
Pink - light green
Dark green - light blue

 

[Sonreir]

Possible.

Each turn signal should have its positive wire hooked up to either the orange or blue wire in the harness (depending on the side it's on) and the negative wire should be grounded through the frame or to a green wire. You can always disconnect the rear signals if you want to test things, but make sure the orange and blue wires don't touch any bare metal while they're disconnected.

 

[nightpoison]

Possible.

Each turn signal should have its positive wire hooked up to either the orange or blue wire in the harness (depending on the side it's on) and the negative wire should be grounded through the frame or to a green wire. You can always disconnect the rear signals if you want to test things, but make sure the orange and blue wires don't touch any bare metal while they're disconnected.

yes sir.

For the front I have the red wire (flasher positive) running to orange and blue on the harness for their sides. black/white (ground) is running to green wire on the harness and then the black wire(running light positive) is running to orange/white and blue/white on the harness for their sides.

for the rear I have the black/white(ground) connected to the green wire on the harness and the red (flasher positive) running to the orange and blue harness wires depending on side. the Black wire (running light positive) I have taped off with electrical tape.

I have no blown fuses, everything else seems to be working fine.

 

[Sonreir]

I don't think your switch supports running lights. Where are the orange/white and blue/white wires you're talking about? Usually those come from the switch.

 

[nightpoison]

I don't think your switch supports running lights. Where are the orange/white and blue/white wires you're talking about? Usually those come from the switch.

the orange/white & Blue/white wire is on the harness. The harness has a solid light blue wire, and a solid light blue wire that has a white band across the top of it, also set up the same way with orange. I'm using the Clymer manual for the bike and at the back of it it has a wiring diagram that includes three wires coming out of the front turn signals. light blue, green, and light blue/white. I assume the harness wire that is light blue with the white band is that wire in the diagram. I attached a scan of the wiring diagram I'm using.

 

[Sonreir]

I don't think that diagram is correct.

Skip the running light connections and see what happens.

 

[nightpoison]

I don't think that diagram is correct.

Skip the running light connections and see what happens.

I took the running light cables out, nothing

I have a set of single filament lights and tried that in the front, nothing.

I connected single filament signals on the front and back for just the left side, nothing.

I don't believe the turn signals are getting any power at all.

 

[Sonreir]

Turn the bike on and measure voltage on the gray wire leading into the left hand control.

 

[nightpoison]

Turn the bike on and measure voltage on the gray wire leading into the left hand control.

if I used the multimeter correct, 10.45v

11.10v at the battery

 

[Sonreir]

OK. And on the left hand control, measure resistance between brown and brown/white with the control switched left and then again between brown/white and dark green with the control switched right.

 

[nightpoison]

OK. And on the left hand control, measure resistance between brown and brown/white with the control switched left and then again between brown/white and dark green with the control switched right.

ok if I did this correctly I got zero for resistance. I disconnected the wires from the bikes harness. I took the negative line on the multimeter and connected it to the brown wire coming out of the Left Hand Controls and then the positive line on the multimeter to the Brown/white wire coming out of the Left Hand Controls. I then switched the Left Hand Controls to the left position. this is what you suggested, correct?

I did the same with the brown/white and the Dark Green wires as well. same result.

Im assuming my left hand control is not working. correct?

 

[Sonreir]

What number do you get when you touch the two multimeter leads together?

 

[nightpoison]

What number do you get when you touch the two multimeter leads together?

when I touch the leads together the screen displays 00.0

when I do the steps above the screen displays 0.L

 

[Sonreir]

0L means no reading. Possibly a bad switch or bad wire. I'd return the control.

 

[nightpoison]

0L means no reading. Possibly a bad switch or bad wire. I'd return the control.

I cut back the terminals and tested the wires bare, and its giving me a reading of 00.0. Its no longer showing 0.L.

I'm going to redo the connections and try the turn signals tomorrow.

Sonreir you have been extremely helpful. Thank you!!!!! I'll let you know when I redo the connections and see if things start working.

 

[nightpoison]

0L means no reading. Possibly a bad switch or bad wire. I'd return the control.

So re did the connections and im good with the turn signals. They are now working. The odd thing is the indiclight only lights up for one side not both. I switched the wires for the indicator and its only one side. The positive line not the negative. Can i just make a splitter for this?