surfish95747
Active Member
Okay, I have a 1980 cb750k that has gone through quite a few revisions. From stock I tore it down and added LED lights, LED flasher relay, café bars, rebuilt forks etc. It was fun, everything worked, except the engine was gutless.
This time around I have Converted a set of 2005 Yamaha R1 forks and whole front end to work with my frame, 1996 cbr600f3 rear wheel, rebuilt the top end (new pistons/rings, gaskets, valves etc). Now the engine runs amazing, even without syncing the carbs (just haven't gotten to it yet) and I haven't done a compression test yet so I haven't compared that to the before. I was going to attempt K&N pod filters and building electronics boxes/battery boxes etc but I decided to just stick with the stock airbox and battery/electronics cage.
At this point I did plug in the vital wires (fuse, everything on the battery cage except the led flasher relay, and the headlight) to ride it and test it. This thing is fun. 59 inches from wheel to wheel, 24 degrees of rake and 3.96 inches of trail on the front end. It is a blast to ride around town so far. Haven’t done anything high speed yet as now I want to get the electrical everything working. I hooked up the headlight to the stock harness and stock left hand control switch. Started the bike with the stock ignition and the headlight lit right up, ran the bike and tested the charging system and at 5000rpm it went right to 14 volts and consistently climbed slowly from there as I held the rpms at 5000.
Okay now to the problem. Now, I cannot get my headlight to work or the turn signals.
Now, these are the only things I have done this time around (and after testing the charging system with the headlight). I bought a 2005 Yamaha R1 ignition to use with my cb750 wiring harness. I did this so that the front end would have a clean look with the R1 top tree and ignition. All I did was basically bypass the parking wire in the stock ignition. I cut the wires from the R1 ignition, cut the wires from the wiring harness and hooked up the wires in a trial and error fashion. What worked was the red battery wire from the harness to the red wire from the ignition (which I cannot find an easily readable diagram, hence the trial and error), the brown ignition wire to the harness ignition black wire, the brown harness TL2 wire to the ignition black/blue wire and the Brown/white TL2? harness wire to the ignition blue/yellow wire.
These are the wires from the R1 ignition
This allows the battery to start and the rear tail light comes on (tail light wires are set up exactly how they were when I had everything working, no change), and I am able to start the bike right up, no problem. I did not attaché the parking wire, but seeing as how it just routes into the brown TL1? wire and my R1 ignition does not have that function, I figured to harm no foul right? It seems to work and function. I even hooked up the Brembo brake switch to the lever and the brake light lights up and everything, although sometimes it acts as if there is a short and wont light as bright or at all. It is just the Brembo switch wires connected to the stock right hand control switch wires.
The other thing I did was I disconnected the white/green wire from the wiring harness and the left side control switch because I was going to go with an aftermarket left hand control switch, but decided to bag it and just go with stock for now. So I hooked the white/green wire going from the harness to the left and control switch horn plug and reconnected the green horn wire to the stock left hand control switch horn plug. Shouldn’t be any different than before I cut them.
Now, when I plug in the headlight and the front turn signals, they don’t work, or the horn for that matter. I did notice as I was stuffing wires into the headlight bucket, the rear yellow turn signal lights lit up a couple times even though my ignition was turned off. I guess I must have touched them to the metal bucket? I don’t know. I have aftermarket front non led bulb turn signals, same as before when it worked, and they have two wires only, so now running light wire. I have the left turn signal black wire plugged into one of the green ground wires, and the left red wire into the orange wire that comes from the wiring harness and the left hand control switch. The right side turn signal black wire is plugged into the light blue wire that comes out of the wiring harness and the left hand control switch with the red wire is plugged into the other green ground wire coming out of the wiring harness.
This was exactly what they were plugged into before when everything was working (I took pictures of how things were wired so I could do it the same this time). The only time I can get a turn signal to light up is if I plug one of the turn signal wires to the green ground and the other wire into the orange/white (for the left side for example), but that orange white wire is for a running light wire from a turn signal, so I stay away from that since I don't have one. . Then the turn signal stays on and then turns off when I flip the turn signal switch to the left. I really just cannot understand why the headlight doesn’t work now! I even plugged in the stock ignition and tried it with that. Still doesn’t light up. Battery has 13.5 volts resting and is a lithium Ion battery.
Well sorry for my rambling and I hope this makes sense. If anybody has any idea why I cannot get the front turn signals, headlight and rear turn signals to work, any advice or suggestions would be appreciated.
Here is a 1980 cb750k wiring diagram incase anyone needs a look. Hopefully it shows up.
This time around I have Converted a set of 2005 Yamaha R1 forks and whole front end to work with my frame, 1996 cbr600f3 rear wheel, rebuilt the top end (new pistons/rings, gaskets, valves etc). Now the engine runs amazing, even without syncing the carbs (just haven't gotten to it yet) and I haven't done a compression test yet so I haven't compared that to the before. I was going to attempt K&N pod filters and building electronics boxes/battery boxes etc but I decided to just stick with the stock airbox and battery/electronics cage.
At this point I did plug in the vital wires (fuse, everything on the battery cage except the led flasher relay, and the headlight) to ride it and test it. This thing is fun. 59 inches from wheel to wheel, 24 degrees of rake and 3.96 inches of trail on the front end. It is a blast to ride around town so far. Haven’t done anything high speed yet as now I want to get the electrical everything working. I hooked up the headlight to the stock harness and stock left hand control switch. Started the bike with the stock ignition and the headlight lit right up, ran the bike and tested the charging system and at 5000rpm it went right to 14 volts and consistently climbed slowly from there as I held the rpms at 5000.
Okay now to the problem. Now, I cannot get my headlight to work or the turn signals.
Now, these are the only things I have done this time around (and after testing the charging system with the headlight). I bought a 2005 Yamaha R1 ignition to use with my cb750 wiring harness. I did this so that the front end would have a clean look with the R1 top tree and ignition. All I did was basically bypass the parking wire in the stock ignition. I cut the wires from the R1 ignition, cut the wires from the wiring harness and hooked up the wires in a trial and error fashion. What worked was the red battery wire from the harness to the red wire from the ignition (which I cannot find an easily readable diagram, hence the trial and error), the brown ignition wire to the harness ignition black wire, the brown harness TL2 wire to the ignition black/blue wire and the Brown/white TL2? harness wire to the ignition blue/yellow wire.
These are the wires from the R1 ignition
This allows the battery to start and the rear tail light comes on (tail light wires are set up exactly how they were when I had everything working, no change), and I am able to start the bike right up, no problem. I did not attaché the parking wire, but seeing as how it just routes into the brown TL1? wire and my R1 ignition does not have that function, I figured to harm no foul right? It seems to work and function. I even hooked up the Brembo brake switch to the lever and the brake light lights up and everything, although sometimes it acts as if there is a short and wont light as bright or at all. It is just the Brembo switch wires connected to the stock right hand control switch wires.
The other thing I did was I disconnected the white/green wire from the wiring harness and the left side control switch because I was going to go with an aftermarket left hand control switch, but decided to bag it and just go with stock for now. So I hooked the white/green wire going from the harness to the left and control switch horn plug and reconnected the green horn wire to the stock left hand control switch horn plug. Shouldn’t be any different than before I cut them.
Now, when I plug in the headlight and the front turn signals, they don’t work, or the horn for that matter. I did notice as I was stuffing wires into the headlight bucket, the rear yellow turn signal lights lit up a couple times even though my ignition was turned off. I guess I must have touched them to the metal bucket? I don’t know. I have aftermarket front non led bulb turn signals, same as before when it worked, and they have two wires only, so now running light wire. I have the left turn signal black wire plugged into one of the green ground wires, and the left red wire into the orange wire that comes from the wiring harness and the left hand control switch. The right side turn signal black wire is plugged into the light blue wire that comes out of the wiring harness and the left hand control switch with the red wire is plugged into the other green ground wire coming out of the wiring harness.
This was exactly what they were plugged into before when everything was working (I took pictures of how things were wired so I could do it the same this time). The only time I can get a turn signal to light up is if I plug one of the turn signal wires to the green ground and the other wire into the orange/white (for the left side for example), but that orange white wire is for a running light wire from a turn signal, so I stay away from that since I don't have one. . Then the turn signal stays on and then turns off when I flip the turn signal switch to the left. I really just cannot understand why the headlight doesn’t work now! I even plugged in the stock ignition and tried it with that. Still doesn’t light up. Battery has 13.5 volts resting and is a lithium Ion battery.
Well sorry for my rambling and I hope this makes sense. If anybody has any idea why I cannot get the front turn signals, headlight and rear turn signals to work, any advice or suggestions would be appreciated.
Here is a 1980 cb750k wiring diagram incase anyone needs a look. Hopefully it shows up.
