Topic: Electrical failure '77 cb550

[Stan]

I was riding the other day when my bike just quit - no indicator lights, no headlamp or horn, no starter - just dead, dead, dead ! Any suggestions on where to begin the process of elimination ? Starter solenoid ? Battery is good, bike was running fine. What gives ?

[tom8Toe]

Stan, when you find out what caused it; let us know as I'm having the same issue with my 400/4. I've now killed 3 batteries in the same number of months, replaced the regulator and rectifier and now trying a dry cell battery to see if maybe the cheapo batteries I was using before were the culprit.

[TwoTired]

Check your main fuse.  Don't just look at it, measure it, or replace it.

Check your Key switch and the plug that goes to it.

[narcoticrex]

Check your Key switch and the plug that goes to it.

+1 to this, this happens on my bike.  same exact symptoms you describe.  jiggle around the plastic connector going to the ignition switch (i pulled the lower part up with a strategically placed zip tie)

[OldSchool_IsCool]

Dirty fuse holders will heat the end caps of your fuses.  Hot enough to melt the innards.  The weird thing is that the fuse will LOOK good.  That's why TT is saying to measure/replace your fuse(s).

If it turns out that you have a melted fuse, shine up your fuse clips.  Pinch them closed too.  If the clips are shot, consider converting to blade fuses.  I think there are some FAQ write-ups on how to do that.

15 amp fuses - don't leave home without some!

[Hope]

+1 on the main fuse.  I blew the main fuse on Jasper & it sounded identical to your problem. (76 550F)

[76 cb550]

My PO put a 15 blade fuse under the seat running off of the battery...If you can't find the culprit might want to look for any "improvements" that past owners have made.

[GNXFan]

My K1 did the exact same thing. Replaced the entire fuse box and have never had that problem again. As previously stated it could also be the ignition switch.

[edbikerii]

+1 on main fuse.

I've had mine die suddenly for two reasons:

The first problem was that I had some wires chafing against the frame.  The chafing had worn through the harness wrap and through one of the wires.  Whenever I made a full-lock turn (I don't remember whether it was left or right), the fuse would blow and everything would die.  I fixed this with electrical tape, and it has been fine for several years since.

The second problem was with the brand new Lockhart mini aluminum housing turn signals I installed.  One of the wires in the pigtail had come loose and shorted out against either the base of the socket or the housing of the turn signal.  This was a bit baffling for a while.  I stood around staring at it while stuck at the side of the highway for about a half hour before I finally got lucky.  I noticed that when I replaced the fuse the running light didn't light up.  Then after a second or two the fuse blew again.  My advice for troubleshooting this kind of thing is to think about any modifications you have made recently, even if you think "they are brand new and couldn't possibly be broken already".

Good luck

Ed

I was riding the other day when my bike just quit - no indicator lights, no headlamp or horn, no starter - just dead, dead, dead ! Any suggestions on where to begin the process of elimination ? Starter solenoid ? Battery is good, bike was running fine. What gives ?