Author Topic: 1977 CB550K Electrical paroblem  (Read 702 times)

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keener

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1977 CB550K Electrical paroblem
« on: May 24, 2008, 04:40:54 PM »
Hey all, well my first post.
I got a new Battery today and the polarity was backwards on the one they gave me from their computer so when i started installing it smoke started coming from the electrical cluster behind the left body panel. I removed the battery quickly and noticed It was backwards. Went and got the old Battery just to make sure everything was OK it was still charged enough to start the bike. Right away the bike started no problem then after running for a second it shut off and the instrument lights went out. I replaced the fuses and the lights came back but when I pressed the start button the lights went out again.
The smoke was caused by the secondary wiring insulation and there are 2 or 3 small sections that are showing bare wire. By secondary I mean the black tubing that holds together clusters. I am going to re-wrap the wires that are showing and I am wondering if any other areas could have been affected by my stupidity like the starter or any solenoids. The bike has 20K miles and ran well before this. all the components look to be ok except for the showing wires. I just got this bike and am still cleaning it up. Any help would be great!!!


Chris

Offline TwoTired

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Re: 1977 CB550K Electrical paroblem
« Reply #1 on: May 24, 2008, 05:45:35 PM »
The rectifier behaves like a direct short when wired backwards, and it is not fused.  (Honda technicians are supposed to know better than wire the bike backwards and if they don't learn this quickly, they find jobs in other trades.)  Anyway, this makes all the wires between the rectifier and the battery heat up and melt their insulation.  Any wires routed near them in the wire harness also have their insulation melted.  Find the rectifier and replace any wire that doesn't have proper insulation.  Follow these melted wires into the harness and keep unwrapping the harness until you stop finding melted wiring to replace.

The rectifier may be damaged, too, so measure it (see the FAQ). 

Good luck.

Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

Those that learn from history are doomed to repeat it by those that don't learn from history.