Electrical Issues

[TripleNickel90]

My "restored" 1974 CB750 K4 is having some issues. I bought the bike last year from "a guy that restores CB750's". It was fully functioning and , after trying to replace the headlight and headlight bucket the other day, something was accidentally disconnected. Now, the lights won't function together, the bike now starts in accessory mode (could have done that before, I didn't notice), etc. Trying to work the problem, from headlight to taillight, every spot I can think of has been checked. I thought the ignition switch might have gone bad.....and when I disconnected it one of the wires' soldering had broken. After repairing that it still didn't work so I bought and installed a new ignition switch. That didn't stop the bike from starting in accessory mode either. I just ordered a $94 wiring harness from vintage750.com and I'm gonna have to rewire the whole thing, unless someone has a suggestion. Each wire has been tested and labeled. The coloring/aging on the wiring harness that is currently on there suggests that it is fairly new, so I'm a bit skeptical as to whether or not the wiring harness even needs replacing.
Please, any insight from previous experience would be GREATLY appreciated and much needed.

 

[hinksy]

Do the earlier CB`s have an " Accessory mode " ? I thought it was only off/on/park . You`re maybe connecting the wrong wires . It`s easy to do as some of the colours seem similar . I had a hell of a time getting blinkers to work untill I finally realised the grey wire was the white from the reg . It is easy to tell if you have a new harness as the main red power wires are the same guage as the rest . On older bikes , these are much thicker

 

[drgnrdr750]

If it was me I wouldn't have bought a new harness. I would of got out the wiring diagram and start tracing the wires to make sure everything is good. Getting a new harness still means that you have to connect everything correctly. Personally finding the problem would be good experience, that is if doing wire work is something you can tackle.

 

[cmg]

My experience w a new harness is that at least 2 of the wires will be a different color.
Compare the 2 harnesses and u will find it

 

[hinksy]

My experience w a new harness is that at least 2 of the wires will be a different color.
Compare the 2 harnesses and u will find it

That happened to me also , but it was half the fun ( not ) You have to look at where it is made and what market it is for . I`m in australia and I got an american reproduction , so it had to have some changes done to it . Luckily they were things I could do easily over an afternoon in the shed and a couple of cold snacks

 

[cmg]

Cold snacks are definitely helpful.