Author Topic: Electrical problem  (Read 1994 times)

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Kalashnikov

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Electrical problem
« on: May 30, 2006, 08:05:13 PM »
I've got a 1975 Honda CB 550 that I'm trying to fix the electrical on. On the front part of the bike, two wires, yellow/green and black come off from the brake line. What would this be? They are unhooked and I don't see where they would connect. There is also a connector that comes off the main harness by the battery compartment (except on the other side) that has green/red and light green/red wires that has no where to connect to. It has power though. The safety unit starting mottor is unhooked too and I don't see where it would hook up. The light green/red green/red has a connector with perpendicular slots. It can connect to the safety unit starting motor by only 1 connector. It has 5 wires comming from it. From what I understand, the starter magnetic switch is not necessary for the electrical to work. The black and red/yellow wire that come off do not have power. I don't see what else would be wrong. I turn the key and nothing happens. The wires for the ignition  don't all have power. It seems as if only the black wire works. The rear blinkers work when hooked up directly. The brake light has power when hooked up directly, but doesn't light up, so I assume a burnt bulb, although it looks fine. In my fuese are good (the 3 in the box) although I'm only getting power to the first fuse. What could be my problem?

If my starter magnetic switch is dead, that means electric start won't work, right? What else does the electric start require, just the starter?

Offline csendker

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Re: Electrical problem
« Reply #1 on: May 30, 2006, 08:33:55 PM »
Quote
On the front part of the bike, two wires, yellow/green and black come off from the brake line. What would this be? They are unhooked and I don't see where they would connect.

The front brakes are hydraulic, and there is a pressure switch in the middle of the brake line that indicates when you are using the front brake.  That's the black and yellow/green.  They should dive into the headlight bucket and connect to like colored connectors buried somewhere in the rat's nest of wires.

Quote
green/red and light green/red wires that has no where to connect to.

Not too sure, but the neutral switch has a single red/green wire and the oil pressure switch has a single blue/red wire. I'm getting a bit lost here, but the neutral switch impacts the bike starting.  I posted a copy of the wiring schematic here --> http://www.sohc4.us/gallery/v/members/personal/Christopher/CB550Schematic.JPG.html?g2_navId=xada3c7ff

I've found that typically like-colored wires connect together and the same for any oddball connectors.  You just have to dig for them.  Now if the harness has been comprimised...

Also look here --> http://www.sohc4.us/forums/index.php?topic=1012.msg31085#msg31085

« Last Edit: May 30, 2006, 08:47:21 PM by csendker »
Actually runs --> 1975 CB550-K1
Projects ---> Crusty old boat
Gallery --> http://www.sohc4.us/gallery/v/members/personal/Christopher/?g2_navId=xada3c7ff

Offline 750duo

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Re: Electrical problem
« Reply #2 on: May 30, 2006, 08:56:42 PM »
Kalashnikov

With so many wires loose you are going around in circles.

My first suggestion is:  Get a copy of the WIRING DIAGRAM.

The first axiom of electrical troubleshooting is : make sure the circuit is wired correctly with all the items of the circuit in place and that the battery is fully charged. The various connections and wire color codes can be found on the wiring diagram.              

Pick one circuit to troubleshoot - (ONLY ONE- not all of them at once) - After that circuit is working properly, then pick circuit #2. Then Circuit #3, etc. (Sometimes you do not have to go through all of the circuits to fix all the problems)

Start with the Starter Circuit

The starter circuit contains the battery (fully charged and connected), the wires (make sure they are connected where they are supposed to go and that the connectors have zero resistance between contacts), the ignition switch, fuses, the starter button, the starter magnetic switch (starter solenoid), and the starter motor itself.

There are ways to check each of the components of the circuit - but the first thing to do is to hook it up completely and correctly. Then if it doesn't work, you can refine your checks until you find the bad component.


Good Luck - Tom
1970 CB750 K0
1976 CB750 K6
1973 CB750 K3

Offline nteek754

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Re: Electrical problem
« Reply #3 on: May 31, 2006, 04:42:17 AM »
Im betting it your brake light wires for the front brake if the wires are good turn key on and touch the two wires together rear brake light will come on
seven fifty four ever its not the destination its the journey Ive been collecting these old dinasours for 33 years . they are quite an ICON

Kalashnikov

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Re: Electrical problem
« Reply #4 on: May 31, 2006, 07:22:28 PM »
I opened up the head light and was greeted with a mess of unhooked wires. I think I found my problem. There is quite a cluster in there. Although I'm still not sure about the connector ar the rear since there aren't any other conectors that look similar.

Offline csendker

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Re: Electrical problem
« Reply #5 on: May 31, 2006, 07:43:43 PM »
Quote
I opened up the head light and was greeted with a mess of unhooked wires.

I didn't realize what I was getting into when I swapped out my handlebars.  It looks quite intimidating, but it's not really.  Get a good, strong worklight and clean up the wires so you can see the actual colors.  Clean up the connectors while you're in there too.  Have your wiring diagram handy, but it's essentially like color to like color and the connectors should match up.  I think I either hit paydirt on the first try or had maybe one screwed up.  And I saved the beer until I was done.
Actually runs --> 1975 CB550-K1
Projects ---> Crusty old boat
Gallery --> http://www.sohc4.us/gallery/v/members/personal/Christopher/?g2_navId=xada3c7ff

Kalashnikov

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Re: Electrical problem
« Reply #6 on: June 01, 2006, 07:19:16 PM »
I connected most of the wires inside the headlight housing. When I turned the key I had power. The nuetral and oil lights came on and the two front blinkers. The horn works and the brake light works when pressing the front brake. When I put the blinker on the right, there was a beeping sound and both the blinkers blinked, as well as the nuetral, oil, and the trun signal indicator. Then a fuse blew. I also had to hold the switch to the right some times or else the blinkers would go off. Just the beeping came when I put the switch to the left. The headlight didn't light up and neither did the high beem light when I flicked the switch up. I'm still only getting power to the main fuse, the other 2 have no power. In the front there are orange/white and light blue/white male connectors that ahve no female ends that I can see. I believe these to be fore the blinkers. There are also some black wires with orange, light blue, orange/white, and light blue/white on them that I'm not sure where they go. The one with orange was plugged into the orange wires already so I'm assuming the light blue goes with the light blue wires. The rear blinker has no response and I know the bulbs are good on them. There were brown and black/red female connectors that are also empty. I don't even see any black/red on the wiring diagrams. There are also quite a few other black wires (male and femal connectors). Does it matter where each go as long as they are black?

Thanks


katfl0res

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Re: Electrical problem
« Reply #7 on: June 02, 2006, 03:25:48 PM »
Hi everyone.  Wow this sounds a lot like the bike I just picked up.  I bought it with a Windjammer fairing, and the person responsible for install totally mangled the wiring behind the headlight.  Now I only have a wiring diagram for a K2, and mine is a K4, so there is some guessing in what I am about to say.  Your blinkers are orange (left) and light blue (right).  One blinker wire connects to its respective colored cluster, the other to ground (green).  Your headlight runs on a white wire, blue wire and ground.  Blue goes to the switch and indicator, and white just goes to the switch.  This is where I am stuck at the moment.  I am left with two black wires open (both male) and a brown (male also).  Nothing seems to happen when the blacks are touched, but I blew the 15A fuse when I accidentally touched the headlight ground wire to it with the ignition on.  Now after everything my headlight and hi-beam indicator don't come on but everything else works.  I took a peek at the 750 wiring diagram on this site, but it is not the same.  Anybody have access to a wiring diagram for every model to help us n00bs out?  They seem to change by year...

Offline TwoTired

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katfl0res

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Re: Electrical problem
« Reply #9 on: June 02, 2006, 06:01:03 PM »
many thanks