Topic: Where to start with electrical?

[tbk125]

So I bought a 75 cb550 non running.  I hooked up a battery for a second and hit the starter and it turned over.  I disconnected it for a second then reconnected it, then smoke started pouring out of under the seat / where all electrical plugs are.  So I know nothing about electrical.. where do I start to get this straightened out? Also what is the best thing for old electrical, replacing everything?

[bjbuchanan]

Check fuses and find what you melted. Until you find stuff melted we can't help.

Report back. Pics help. It's alright if you don't know exactly what it is, describe it real good including wire colors that go to it

[donny]

 
          You have just entered Electrical Hell.

 With these old bikes;  You will be an expert in time.

             Lots of electrical info in the archives.   The old bikes I bought I was forced to completely rewire,
   ( just the basics).

Good Luck.

[tbk125]

well here is the pictures I'm not sure they are going to do any good but..


side view

top view

I believe the smoke was coming from the red wire

the other electricals, this was not smoking

[rb550four]

If you don't have a shop manual you should get one.That will give you the understanding that you will need about the entire machine,
https://www.google.com/webhp?sourceid=chrome-instant&rlz=1C1TSNP_enUS484US484&ion=1&espv=2&ie=UTF-8#q=1975%20honda%20cb550%20wiring%20diagram
but there are wiring diagrams on line so you can trace out your wires, see where they come from, see where they go, and what they do. This is the place to start... now you can follow the path from the battery, find the damage, find out what would have caused it, and then repair it.
The wires are color coded and identifiable with the wiring diagram. It's not that hard, just take it easy,find the color codes in the diagram  and the colored wires on the bike. It'll all make sense when it sinks in, no cutting until you are sure you found the issue for sure. solder the splices and shrink wrap , use the same color-same size wire if possible so's you don't get all messed up next time you get into the wires. Have fun with this, it's winter, and you are learning something, no racing through it ,do it right ,be proud of your work and have a great time. It can be very enjoyable if you let it .

[Bodi]

OK.
Almost certainly, you hooked the battery up backwards the second time. It's easy to do, and many of use (me too!) have done it.
This fries some important parts and can melt wire insulation inside the sheath, causing wires that should NOT touch to do so because their insulation is melted.
This is not the end of your bike. If you disconnect the rectifier - I think it's the bottom metal thing in your first  picture, just pull the plug - you should be able to hook the battery back up ("-" to the big black wire to ground, "+" to the big red wire to the solenoid) and the bike should pretty much work normally (but never charge the battery without a new rectifier). Connect the ground first. If you see a big spark and maybe some smoke from somewhere when you touch the red wire to the battery terminal, stop and find what's happened - probably the melted insulation problem. The starter may also not work without the clutch pulled in, another inexpensive fried part, but there isn't anything else on a stock bike that should be damaged. If it has an aftermarket electronic ignition though, that's probably junk as well.

[dave500]

I rarely post in electrical threads as you have to explain too much #$%* that no #$%* understands, but im with bodi here,reversed polarity,its all too common!

ive never ever done it though I will have you know!

[rb550four]

I find it amazing that it happens so often Dave, I have never done it either and can't see how it can happen, but if you say it's so, it probably is. One would have to pull and tug, then cross the wires over each other then twist the ends to get them on the terminal. The alarm should be going off at the pull and tug part.
Even if you put the battery in backwards , the alarm should go off when you can't use the screwdriver you removed it with to re install it.Has anyone put one in upside-down yet?
I'm  still amazed. And  he should still get a manual.

[bjbuchanan]

I find it amazing that it happens so often Dave, I have never done it either and can't see how it can happen, but if you say it's so, it probably is. One would have to pull and tug, then cross the wires over each other then twist the ends to get them on the terminal. The alarm should be going off at the pull and tug part.
Even if you put the battery in backwards , the alarm should go off when you can't use the screwdriver you removed it with to re install it.Has anyone put one in upside-down yet?
I'm  still amazed. And  he should still get a manual.

I haven't done it because I'm very careful but I can see it easily being done.

I worked at an AutoZone during school and some dipsh!t blew 2 side post truck batteries right in front of me loading the battery rack. The positive caps had fallen off and he loaded them facing, thank god they didn't explode my way, I was only about 3 feet away facing them with no protection

[db22]

What Donny said -- if you stick with this for a while, don't lose patience, you'll end up knowing the whole system pretty well. I have two '75s, both 550Ks, and over the course of five years I have learned a lot (most of it here on this forum).  Download the factory manual.  Also, query topics here on the use of much-less-expensive auto electrical components, and get one of Hondaman's automotive fuse holders (stock up on fuses).  Take a good look at all the wiring diagrams you can find, and use the one that makes the most sense to you.  The one in the Clymer shop manual is pretty specific about hooking up the multiple connections in the headlight bucket.  HINT: DON'T open the headlight bucket until you sort out the troubles under the side cover.  One mess at a time . . .

[MiGhost]

I find it amazing that it happens so often Dave, I have never done it either and can't see how it can happen, but if you say it's so, it probably is. One would have to pull and tug, then cross the wires over each other then twist the ends to get them on the terminal. The alarm should be going off at the pull and tug part.
Even if you put the battery in backwards , the alarm should go off when you can't use the screwdriver you removed it with to re install it.Has anyone put one in upside-down yet?
I'm  still amazed. And  he should still get a manual.

From the top view pic above. You can clearly see that the battery cables are not original, and extremely overlength. Not unusual once the corrosion eats the end of the original cables. If the OP did what anyone would have done by just letting the cables hang once they were disconnected. The crossed cables will become obvious.

The cable laying where you would expect the ground is actually the positive cable. You can see how it routes down towards the rear fender to the solenoid. The ground cable hangs over the side of the bike looking like it attaches to the rear post on the battery.

Given that arrangement of the cables. I would suspect that anyone would make the same mistake without even thinking about it.

Once the repairs are taken care of. Those battery cables need to be taken care of also. They need to be about 3-4" shorter to eliminate the possibility of them getting crossed again.