Topic: 78 CB550K Electrical and Diagram Issues

[jjb]

Hey all,

Before we all get excited about diagnosing another electrical issue...  I've solved the problem... sort of i guess. 

I'm new to 'posting' on this forum but have been digging up info here for a while now.  Sorry it's taken so long.  This place has been an absolute savior.  Thanks!

Wanted to share my experience, in as few words as possible...

Problem started a year ago.  My tail fuse started to blow and thus my dash and running tail light did not work.  It's been so long now i don't even recall how it all started.  Either way i messed around with the wiring many times to no avail.  Always referring to the wiring diagram in my manual.  First mistake!!  Colors didn't always match up! I've read almost every post on here about troubleshooting a constant blown fuse and finally fixed the problem today!  Feels good!  The problem is in the handlebar blinker switch.  I've disconnected that wire and everything works again.  Which is odd because now I'm not sure what that wire/connection did in the first place???

Here's the deal.  We all know the 78 550K is an odd ball.  Well, the wiring diagram in all the manuals and most on line don't match all the color codes right.  Today I found a wiring diagram for a 77 750K and that was bang on.  Irrelevant but, it actually showed the 2nd brown wire coming out of the ignition switch, for a total of five wires, for the 'Park' light.  Every other diagram i looked at only showed 4 wires coming from the switch so that was first moment i thought it may work out for me. 

Anyway.  Sorry for the long message but the short and skinny is.... if you own a 78 CB550K ignore the wiring diagram in the book and find yourself the one for a 77 750K. It's attached below in case anyone ever has this problem also.   

Thanks everyone for all the posts on this topic and others.  It's truly been a great help. I just wanted to add that little bit extra i worked out. 

[TwoTired]

The wire diagram for the 78 CB550 is correct in the Honda shop manual.  Clymer has pretty colors to please the viewer instead of accuracy.

Cheers,

[Deltarider]

If it's still there, start with the diagram for your area in the owners manual.
For instance, in the manual that came with my bike, there are no less than 4 diagrams:
General type
ED type
U.K. type
U.S.A. type

[jjb]

Thank you both for the info.  Much appreciated. 

I'll have to track down a clear scan of the shop manual.  The quality of the shop diagrams i found were of poor quality and I couldn't follow them. 

Thanks again. 

[jneuf]

I had some fuse issues this past fall with my 78 550K as well...I had a hard time tracking it down, and at one point my main fuse actually started to melt the fuse holder.

I decided to wire in a blade type fuse holder, and put a lot of miles on the bike afterwards, and never had a single issue...I didn't expect it to actually fix any problem, however, I just thought I should replace the old melted holder....