Topic: 74-550 Wiring Questions

[Chrisboden]

Is the 500 and the 550 wiring schematic the same?

My ignition switch is wonky, is it possible to remove it and replace it with a pair of toggle switches?
Is it possible to replace it with a singe toggle switch with a 1-o-2 DP4T setup?

The ignition switch has 3 settings, Off-1-2, what are these for and what do they mean? Note, my ignition isn't on the head, it's down under the gas tank on the left side ahead of the engine mounted to the frame.

How hard is it to find a brand-new wiring harness for this bike? At 30 years old I'd like to replace it all. If I can't find a harness, I'd like to get a PERFECTLY accurate schematic and rewire it from scratch given that for such a simple system that's only a one afternoon job, if that.

[Paul]

Wiring loom is different for the 550 and the 500
Ignition switch off - off!, 1 - power to the main system, 2- power only to the tail light (Parking)
Wiring diagrams (manuals) are available on the "Honda4fun" website if not here somewhere.  and yes a DPST will do for basic ignition if you don't mind the chance of it being nicked. and ignore the "parking" function.
I've attatched the loom wiring diagram if it doesn't open let me know and I'll mail you a copy.

[attachment deleted by admin]

[Chrisboden]

Thank you, but you said the 500 is different from the 550, and gave me the manual for the 500

I have a 550

Thanks for the ignition tip, tha'ts very cool. I can't imagine a need for the parking lights, so yeah, just swapping that out for a DPST will work great. As far as it getting stolen, I can use a keyswitch I just want to get rid of the crap ignition switch.

[SteveD CB500F]

The switches are only crap when they're worn.

You can buy a NOS switch with keys from David Silver (plus others) - check the new "Online Resources FAQ"

[Harry]

Thank you, but you said the 500 is different from the 550, and gave me the manual for the 500

I have a 550

Honda4fun have the wiring diagram for the 550, you need to look about a bit!

[Paul]

Sorry 'bout the wrong drawing.....didn't read properly. However in the manual I have I have a few drawings for the 550 aswell. I didn't realise the size of the file - but it got in anyway, I can do this again if the size is OK... (Moderators comments ??) or mail direct.?

[Chrisboden]

Got the email, you guys rock, thank you

I plan on rewiring this thing completely from scratch. When I do, I'll post detailed instructions and a how-to on my site.

[Glenn Stauffer]

The CB500 and CB550 wiring diagrams that were attached to this topic thread have been moved to the SOHC/4 website:

http://sohc4.us/?q=node/178

--Glenn

[chippyfive50]

I did a point to point harness for my 71' 500 with a 550 motor this winter, and the difference is amazing. You can get all of the spade clips from Honda or possibly(jameco electronics, my 71 used molex connectors(round pins)).  I moved all of my switches into the headlight bucket, sans the horn and turn signals which were no longer needed( open headers/ arms) . I do a bit of wiring for work(control systems , bread boards, and am decent with an iron. I thought it would be a one day job.....until the day was over. It is quite tedious getting the  lenghts correct and the wires nice and tidy( I used some nylon loom).  I was amazed  my bike even ran after chopping up the old harness, there was corrosion  six inches up some of  the wires form the terminals when I stripped them back.  oldmanhonda.com has some great elementary schematics(which I employed), and I highly recommend the DYNA S ignition. I rode it 70 miles today, It is like a new machine. 
this got  little hairy.. see pics
good luck, it is worth every hour,
chris.....

[Magmotor]

I just finished wiring my '74 550. Under the left side cover where all the electric is, there are 3 large J-connectors. Pull each one apart and take a good look at em....look for heavy copper corrosion, green color...heavy corrosion will cause a large resistance increase and boo-koo headaches trying to figure out what's wrong.....try to move the male tabs, if they move back and forth, they need to be replaced or bypass the j-connector entirely by splicing the wires together. . I spliced the main alternator wire so no voltage drop can occur within the connector. After 31 yrs these connectors go bad....I bought a 4 wire ignition switch off e-bay and put it between the tac & speedo, like the later '76's & up..the top off a film can fits snuggly over it to protect it from the weather...it has two positions...off/on...all the running lights go on when the headlight is turned on.