1980 KZ550 dead switch

With no spark on plugs, will need to diagnose whether the problem is pre-coil or post-coil or coil itself.

Would begin by determining whether red/yellow wire (from right hand handlebar switch gear) is feeding battery voltage to coil when ignition switch is ON.

Good Fortune!

Fantastic, Thanks Patton and Danhalen! I just came back in from the bike. I had a hunch about the ignition ON position, but you verified it for me Danhalen. I only get juice to the white wire. I'll go back out in the morning and start tracking down why the red & blue wires don't have juice, and then see if I can't figure out why the yellow & brown wires aren't doing their thing. Maybe my brown wire has taken a dive afterall, and I didn't catch it.

I'll also check for spark to the plugs like you suggested Patton, though given my bikes past starting easy, I'm thinking there's no juice to them.... whhiiiiiccchhh would be the result of not aving juice to my red & blue wires at the ignition????

"Whiiiiccch would be the result of the" or maybe the starter switch is independent of the ignition switch? Electricity is the antidote to my ego.

They are two seperate circuits. If you bridge the starter solenoid at the heavy duty teminals, the bike will crank but get no spark to the plugs.

Only when the run/stop switch is in "RUN" will you get spark(assuming the power going to the switch is there).

Ill add that the yellow wire off the key switch is what feeds the stop switch, then goes on to the start button, then to the clutch interlock switch. So i would try what mfolks is suggesting and see if you have any luck. If you have a hard time following the posted wiring diagram, you can try the one in the pdf service manual that's floating around the internet, the diagram is on page 313.

Patton wrote:

With no spark on plugs, will need to diagnose whether the problem is pre-coil or post-coil or coil itself.

Would begin by determining whether red/yellow wire (from right hand handlebar switch gear) is feeding battery voltage to coil when ignition switch is ON....

Absent voltage to coil primary, the coil won't function, and the spark plugs won't spark.

With oem wiring, ignition switch should be ON and the kill switch must be in RUN position.

Should measure voltage at this location to assure voltage is reaching the coil. See image below. Of course, it's possible that the red/yellow wire could be internally broken between there and the coil.

Lack of voltage to coil primary indicates a pre-coil ignition issue. But doesn't guarantee there's not also a post-coil issue or an issue with the coil itself.

Good Fortune!

[Click on image to enlarge view.]

Ok, dawn has come, and I'm really starting to get an idea of what you guys are telling me. I'll give these options a shot as soon as I can.

Thanks for all the advice again guys. It's much appreciated.

Matt

She's up and running fellows. The ignition main wire had corroded on the inside of the switch to the point that the brass plate couldn't contact, much less conduct more than 3 volts. I pitted the corrosion out with a file for now, but I'll probably get a new ignition after the season is done. I'll also be cleaning my contact points.

Question, The red and blue wires in the ignition which lead to the starting switch, do they receive a charge when the main wire has connected with the yellow and brown wires?
If so, is the red wire coming from the taillight which receives juice from the main wire via connection at the ignition?

Also, the main wire is connected to a fuse box afterall, though not the one listed in the diagram, nor as listed in the melted slot in the three point fuse box labeled "main". I am wondering if my model bike (1980 kz550 ltd) had two fuse boxes. The 3-fuse box where the main should be is melted. The second fuse box contains 2 fuses, one of which connects the main. The main fuse folder is showing signs of heating. There is slight melting on the outgoing end of the fuse. The previous owner also put a 30 amp fuse in the line. Could this heating be caused by poor connections?

Should there be two fuse boxes, and if so, then what wire was replaced by the "main" wire when the previous owner put the main into this other box? I ask, because this second fuse box has a rubber grommet it sits in that matches onto the bike frame as the first does... which says to me that it does belong.

I may be purchasing one of those automobile fuse boxes as I've seen suggested to others with elec. issues.

Here's an excerpt from the wiring diagram.

See following post for how to access wiring diagrams and other info for various models.

Good Fortune!

[Click on image to enlarge view.]

Some bike's have aux fuses for items like heated clothing and grips that are available for the rider to use.

They usually are not part of any circuit impotant to the operation of the bike.In the factory shop manuals, they are shown as open ended, that is, it's up to the rider to furnish the other end of the circuit.

Oh, ok MFolks, that would make sense. Thanks for the info!

Thank to you as well Patton.