Topic: 1976 CB550K Wiring Question

[mb108]

I am consulting the wiring diagrams in the Honda service manual and in Clymer, they don't match what I've got on the bike. I've definitely found some "custom" wiring on this bike, so I'm trying to get it sorted.

Comparing diagrams, looks like I might have the proper R hand control pod (kill switch, start button), but the L hand pod looks like maybe it's from the 500. Just turn signal and horn. All that adds up to no headlamp dimmer switch, so it looks like the PO installed a small rocker switch between the speedo and tach...

The R hand pod has a broken starter switch, and the blk, blk/red, and yel/red wires leading from that have all been isolated and wrapped in electrical tape. So electric starter is completely disabled, but is this right? shouldn't the blk/red connect to the blk? Or maybe it doesn't matter because the PO also removed the fuse box. There's just a large red inline fuse in the back... I'll figure that out later.

Also looks like there's no clutch switch (no grn/red wire from anywhere) -- maybe all the L hand controls are from a 500? And assuming it was running, does this hint that the PO eliminated the starting motor safety unit?

For now --  can anybody confirm my theory about the L hand pod being from a 500? And anybody have a good recommendation for a replacement dimmer switch? I don't mind if it is a hack, but the current hack is kinda broken so I need something.

Anyway lots of questions but any help is appreciated!

[thomellis]

If you can put up a couple pics of your controls, someone here can undoubtedly tell you what you're dealing with.

As far as the wiring, there's all sorts of wonky things people have done to these bikes.  The system itself is pretty basic, and when you get some people just splicing wires in all over, and ripping things out, you can end up with a rats nest to figure out later.

You technically don't need separate fuses, but it really is a smart choice.  That way  if the headlight circuit blows, you don't risk cutting power to the whole bike (not that driving in the dark is easy ).  It sounds like the PO was maybe trying to go with a minimal wiring setup, but only got halfway there, based on the disconnected starter, etc. 

What kind of a key unit do you have?  Is it the original (4 wire molex)? If the starter motor safety unit wasn't ripped out, it sounds like it was at least bypassed.

[mb108]

I'll get some pictures up later...

Now that I think of it I also couldn't get the neutral indicator light to come up, that also is supposed to run through the safety unit. I don't mind the bypass or the single fuse that much, just trying to figure out where I stand. Whoever did the wiring did a decent job, but I need to make a couple of mods -- they were running without turn signals and I need those in CA.

The key unit has a four-wire molex plug, but only two wires in it. Probably explains why I couldn't get spark when I turned it to the 2nd setting.