Topic: Electrical issues '73 CB750

[HondaMan]

I thought it was wrong due to scheisse quality LED pilot bulbs that lived several minutes.

I think I also got a set of those LEDs, PeWe, but for my Explorer. They lasted one trip to work (15 minutes) and all burned out.

[Mark K]

I like to print out the color wiring diagram from the old man honda web site. I've been known to glue it to a piece of cardboard and hang it where I can see it with both hands busy.

Finally able to use your idea. Printed out wire diagram on 4 sheets of 8.5 x 11 paper, taped to foam board. Make's it much easier to read. One side is CB750, other side is SL350 (next project).

Thanks for the great idea Don!

[HondaMan]

I like to print out the color wiring diagram from the old man honda web site. I've been known to glue it to a piece of cardboard and hang it where I can see it with both hands busy.

Finally able to use your idea. Printed out wire diagram on 4 sheets of 8.5 x 11 paper, taped to foam board. Make's it much easier to read. One side is CB750, other side is SL350 (next project).

Thanks for the great idea Don!

OK, I'm officially inspired!
I'm gonna do that, too.

[Mark K]

I found what I believe to be an error in the color CB750 diagram. At the top, the starter button is labeled horn. I'm sure someone has noted that before, but initially when I saw that, it confused me 

[TwoTired]

I found what I believe to be an error in the color CB750 diagram. At the top, the starter button is labeled horn. I'm sure someone has noted that before, but initially when I saw that, it confused me 

I find less errors in the Honda Shop manual diagrams.  Accuracy is important to me.  Generic diagrams don’t have the differences in specific model changes.  The colors are pretty, though.

[MauiK3]

I never met a generic aftermarket manual I liked for things like wiring and such.

[PeWe]

Some diagrams are mirrored.

[Mark K]

I believe I have found the problem and corrected it. I had at least two wires not properly connected. My after market harness has a plain brown wire I initially plugged to another brown wire in the headlight bucket. The brown wire in the harness is for the tail light circuit and shouldn't be in the headlight bucket, according to thee different CB750 wire diagrams I've referenced. So I taped the brown wire off. There is also an extra black wire (from the harness) in the bucket that isn't used - taped that off as well. Went back and reread everyone's advice and suggestions in this thread. Along with that and studying the wire diagrams, realized I had the clutch starter green/red connected wrong as well as the headlamp 7a fuse wires (brown/red & brown/black) connected wrong, even after reading one of HondaMan's posts where he detailed where those wires connect.

Purchased a 12v 15A circuit breaker from Amazon, connected to the 15a fuse holder, worked great.

With battery installed & connected, headlight hi/low beam, horn, starter, rear brake, r/h on off light switch all work. I don't have working turn signals (have to order some) and front brake still needs brake fluid/bleeding.

Thanks to everyone who offered assistance, advice and encouragement. Please forgive my stupidity.

[HondaMan]

BRAVO!
You're not a quitter, that's half the battle. Good job!

[grcamna2]

I believe I have found the problem and corrected it. I had at least two wires not properly connected. My after market harness has a plain brown wire I initially plugged to another brown wire in the headlight bucket. The brown wire in the harness is for the tail light circuit and shouldn't be in the headlight bucket, according to thee different CB750 wire diagrams I've referenced. So I taped the brown wire off. There is also an extra black wire (from the harness) in the bucket that isn't used - taped that off as well. Went back and reread everyone's advice and suggestions in this thread. Along with that and studying the wire diagrams, realized I had the clutch starter green/red connected wrong as well as the headlamp 7a fuse wires (brown/red & brown/black) connected wrong, even after reading one of HondaMan's posts where he detailed where those wires connect.

Purchased a 12v 15A circuit breaker from Amazon, connected to the 15a fuse holder, worked great.

With battery installed & connected, headlight hi/low beam, horn, starter, rear brake, r/h on off light switch all work. I don't have working turn signals (have to order some) and front brake still needs brake fluid/bleeding.

Thanks to everyone who offered assistance, advice and encouragement. Please forgive my stupidity.

I'm glad you've got it beat Mark 

[RAFster122s]

Congrats Mark, you have learned some things through the experience you won’t forget. Do not apologize for ignorance, you can be taught to over come ignorance. In my book, Stupidity is when you refuse to learn or try to do so…
Don’t regret asking questions to learn. Sometimes learning the right questions to ask is a skill that takes time to develop as well…
Electrical is a stumbling block for many mechanics, it takes being methodical and thinking about things and sometimes requires you to start over several times in diagnostics and the more you can break it down into bite size pieces the easier it becomes to learn for future sessions. Clean grounds and connections can sort out many problems in bikes and in cars.
You were given good advice and input and you stuck to it and worked through the problems. Glad you were able to sort through it. Congrats…
David

[PeWe]

This will be a good thread for others that WILL get same kind of problems

[bryanj]

The brown wire is for the small sidelight bulb fitted in reflector and used in different countries

[PeWe]

The extra not used brown wire  in headlight bucket will lit my bikes rear light.
K6 stock loom and K2 aftermarket.

[Mark K]

BRAVO!
You're not a quitter, that's half the battle. Good job!

Thanks HondaMan, I really appreciate all of the great information you provided me with on my electrical issue and other problems as well.

[Mark K]

I believe I have found the problem and corrected it.

I'm glad you've got it beat Mark 

Thanks, appreciate the support!

[Mark K]

Congrats Mark, you have learned some things through the experience you won’t forget. Do not apologize for ignorance, you can be taught to over come ignorance. In my book, Stupidity is when you refuse to learn or try to do so…
Don’t regret asking questions to learn. Sometimes learning the right questions to ask is a skill that takes time to develop as well…
Electrical is a stumbling block for many mechanics, it takes being methodical and thinking about things and sometimes requires you to start over several times in diagnostics and the more you can break it down into bite size pieces the easier it becomes to learn for future sessions. Clean grounds and connections can sort out many problems in bikes and in cars.
You were given good advice and input and you stuck to it and worked through the problems. Glad you were able to sort through it. Congrats…
David

Thank you for the great advice and support David.

[Mark K]

This will be a good thread for others that WILL get same kind of problems

I hope someone can learn from the mistakes I made.

[Mark K]

The brown wire is for the small sidelight bulb fitted in reflector and used in different countries

I didn't even think the brown wire could have another use, but sidemarker lights would look good. Tanks for the info!

[grcamna2]

The brown wire is for the small sidelight bulb fitted in reflector and used in different countries

I didn't even think the brown wire could have another use, but sidemarker lights would look good. Tanks for the info!

I've seen certain headlights I've looked at for sale online which have a small type of 'running light' built right into the lower part of the headlight bulb;like maybe 2-5wts and this is not the main(55/60wt.)halogen? type headlight bulb.
A non-USA headlight has these with an OEM handlebar switch for 'Parking light' ? and I like them.
I think European bikes and many others all over the world,just not USA.. I believe that's what that brown wire up front off your harness is designed for along with the handlebar switch that turns-off the main headlight & turns-on that small bulb;helps save lots of alternator output normally going to the headlight.

I want one of those Euro-style headlight bulb/assembly with a replaceable H4 style bulb And the small 'parking light' bulb below it with the option to turn-off the main headlight bulb;the USA laws say the headlight must be on full-time even during the day & with that small 'parking/running light' on it will fulfill the requirement of the law,somewhat.

[RAFster122s]

Sometimes those bulbs have been referred to as City Lights

[PeWe]

Must be a reflector with parking light. My K6 had it as stock, K2 too.
Handle bar switches have P for it.
European models.

[Don R]

 I installed the parking lamp on a cb400F and got another one for my charging system challenged Hot Rod bike. I got the first headlight from Yamiya, it was a Marchal, (sp) This time I got the right control and headlight from DSS. Once I removed the male to male jumper on the 400F the wire colors just matched up.
 I tried a blue LED but it was so blue I thought it would attract law enforcement so I went to yellow.

[grcamna2]

I installed the parking lamp on a cb400F and got another one for my charging system challenged Hot Rod bike. I got the first headlight from Yamiya, it was a Marchal, (sp) This time I got the right control and headlight from DSS. Once I removed the male to male jumper on the 400F the wire colors just matched up.
 I tried a blue LED but it was so blue I thought it would attract law enforcement so I went to yellow.

I run yellow in my bike.

[HondaMan]

Back when these bikes came out (and you had to look out for dinosaurs on your way to work...), a German exchange student who had a 750 in Germany and another in the USA would come to my shop for his oil changes and tuneups. He once told me that the "Park" function of the (750K1/K2 he owned) functioned in Germany as the "parking time limit" feature in major cities across Europe back then. It worked like this: in Germany (Bonn, where he came from) you were required to park a motorcycle off the street, on the sidewalk, to preserve space for cars, and you were limited to 30 minutes in parking the bike there. If the bike was parked and the light, the local gendarme walked by and marked the tire with chalk: if the chalk marks was there and the little light in the headlight and the taillight were no ON, you got a ticket. In the next 'circuit' check by the officer(or officerette, many were women) found the chalk mark, the lights out, and the bike still there, it was impounded. This applied to all bikes.

I sometimes think this is how BMWs got such big batteries...