Topic: Electrical question 77 CB550K

[ArtRuckle]

Hi all. I've got a problem with the Electrics on my '77 CB550K and am hoping someone can give me some direction.

The other night, I drove home with everything working fine, but the next morning when I turned the key, I got nothing. No headlight, taillight, dash, nothing. The whole electrical system seemed to die overnight. Just to make sure I was covering the basics, I charged the battery overnight, so it's at 12.8v and the connectors are tight.

So far, I've gone over the fuses and tried to jump the ignition wires, but am getting nothing. Before I start tearing into anything and everything, does anyone have an idea as to a direction I should take? My other Honda is a CX500 and the electrical systems seem to be just different enough to confuse my few remaining brain cells.

Any and all help would be appreciated. Also, if I've posted this in the wrong part of the forum, please let me know.

Thanks!

[LesterPiglet]

What do you mean by jump the ignition wires?
Check your ignition switch, these break pretty often.

[ArtRuckle]

I pulled the plug off the back, checked the wiring chart, and tried to connect the 'run position with a piece of wire I had. I also put a voltmeter on it to see if there was any juice, but couldn't get that to show anything.

I'll check around for a new ignition switch, too.

Thanks for the reply!

[Johnie]

With the headlight in the on position, flick the ignition switch back and forth and see if you get a flicker of headlight. If you do then you know the contacts in the switch are bad. How old is the battery? I had a 6 month old battery show me volts, but produced no amps. Let us know how you come out.

[ArtRuckle]

Thanks for the reply, Johnie. The PO said the battery was less than a year old about a year ago and as it held just fine last Fall and so far this Spring, I think it's okay. I planned on going to an AGM battery anyhow, so I may be doing that sooner than I think!

I tried the key jiggling and didn't get a response, so I went ahead and ordered a new EMGO ignition switch. It should be here this week and I'll swap it out and post the results.

Thanks again!

[ArtRuckle]

Another update: After researching the EMGO ignition switch, I decided to order the Switchsaver kit from the sohc4shop to go along with the new switch. While I'm in there, I'll take some photos to post so people can se if I'm missing something really obvious.

[ArtRuckle]

Problem solved!

Turns out it was the fuse box. As you can see in the first photo, the plastic was melted around the solder connection for the main fuse. I think what happened was the connection got a little loose and as it drew more current it got hotter, which caused more loosening, which created more heat, etc. I didn't see it until I actually pulled the fuse. Before that, I was just looking at the fuse, which had not blown. The PO had installed a 30A fuse instead of the 15A, so I'm sure that didn't help the situation.

I built an new fuse box, upgraded to blade type fuses, and professionally zip-tied it in place for the time being. I also installed a new ignition switch and am waiting for the relay set from SOHCfour to wrap it up for good. Then I'll keep an eye on things to make sure there are no other problems.

Thanks for your input and direction!

[LesterPiglet]

Always physically check fuses as they can blow at the ends where you can't see the flament is burned out.
Glad you got your problem sorted.

[Johnie]

Yes, she was a bit warm for sure. Glad you got it sorted out.