Tail light and horn issues

Hey all,

I have an 81 kz550a that was someones rat bike and is now mine. I have not had any problems with it, electrically, until a few weeks ago. I took off my instrument cluster (unplugged everything from the headlight) and tachometer and am just running my speedometer. My blinkers work fine, my headlight works, and my stop light works. However my tail light does not come on at all. It does not come on when the bike is off and the ignition is turned on or when the bike is running. I followed the wire up the wiring harness because I thought that I might have messed something up when I unplugged everything, but it all looks good. The only thing I could think is that maybe my ignition is messed up since that is the only other place I could trace the tail light wire. Is there a way to check this? What else should I look for?

Also my horn works sporadically. If I press the horn I will get it to beep maybe once out of 20-30 presses. The rest of the time I can tell that there is power going to it (I can feel it move a little with my finger) but it does not sound. I was thinking that maybe the wiring for it is corroded somewhere or maybe I have a bad capacitor/regulator; does the horn even go to any regulators/capacitors/thingies from the battery to the horn? I have not looked in the switch yet so I guess it might be something in there???

Thanks!

I was recently messing around with the electrical system on my 82 KZ550 C3 and discovered that the running lights wouldn't come on. I found out that it was because the kill switch was disconnected. Take into consideration in my situation the wires to it were cut off and taped together, but when I hooked up my replacement the light problem was solved. So if all else fails have a look there, couldn't hurt.

ajp529 wrote: ...81 kz550a...blinkers work fine, my headlight works, and my stop light works. However my tail light does not come on at all. It does not come on when the bike is off and the ignition is turned on or when the bike is running. I followed the wire up the wiring harness because I thought that I might have messed something up when I unplugged everything, but it all looks good. The only thing I could think is that maybe my ignition is messed up since that is the only other place I could trace the tail light wire. Is there a way to check this? What else should I look for?....

Perhaps the rear bulb's tail-light filament is burnt out.

If needed, here are links to '81 KZ550 wiring diagrams in KZr's FILEBASE.
> www.kzrider.com/filebase/doc_download/301-z550a2
> www.kzrider.com/filebase/doc_download/303-z550d1
> www.kzrider.com/filebase/doc_download/302-z550c2

Good Fortune!

Hey sorry should have mentioned that that was the first thing I did. I will check out the kill switch wiring. Any thought on the horn? Thanks!

the horn just has a keyed hot and a ground that comes from the switch, if it has full voltage and a good ground signal and doesn't work everytime it may need replacement, are you trying when it's running? sometimes if the bike isn't running a worn out old horn wont work easily.

If you've never cleaned the many and various electrical connectors and switches, read this:

Cleaning Motorcycle Electrics

1. Get some of the De-Oxit electrical contact cleaner and figure on spending a good day going from the front of the bike to the back. It’s a plastic safe cleaner/preservative. www.deoxit.com is their website. It can be purchased at most Radio Shack Stores or any electronic supply places. Or use any plastic safe electrical contact cleaner(NOT WD-40 !).

2. On the older Kawasaki's, a majority of electrical connectors are inside the headlight housing requiring removal of the headlight, then the fun begins.

3. Do one set of electrical connectors at a time to avoid mixing up what connects to where. Usually disconnecting, spraying with De-Oxit and reconnecting is about all you'll need.

4. However, when encountering the green crud of corrosion, a brass wire brush may be needed on the pins you can reach. Some 400-600 grit wet and dry sandpaper strips rolled into a tube should reach the male and female pins in the more difficult to clean connectors.

5. Smoker’s pipe cleaners, cotton swabs and wooden toothpicks work as cleaning aids.

6. Really small electrical connectors may require the use of a welders tip cleaning tool assortment.

7. Most pins in the connectors are coated with a thin plating of tin, and others may be nothing more than copper or brass.

8. If moisture is added, the resulting corrosion lowers the voltage/current being carried causing dim lights, slow engine cranking, slow turn signal responce and lower input voltage to the ignition coils resulting in weak spark.

9. The left and right handlebar switch pods will need attention too as they have circuit functions like turn, horn, run/stop, and start. The older Kawasaki’s have reports of the soldered connections crumbling, if your bike has this problem, just ask, as I’ve got a repair procedure for this.

10. Usually a spritz or two with actuation of the switch is about all needed for these switches unless corrosion is detected and then careful disassembly is required.

11. The ignition switch may or may be not sealed to allow spraying the internal contacts. I urge caution if attempting to open this up as springs, and ball bearings may fly out never to be seen again!

12. If your bike has the older style glass tubed fuses, I suggest replacing them as vibration can cause internal failure. AGX is the type used, and most auto parts stores can get them for you, along with boating supply stores.

13. Clean the fuse holder clips, looking for signs of overheating(discolored insulation, signs of melting). I use metal polish on a cotton swab, followed by spraying another clean swab with the De-Oxit and then rubbing the inside of the fuse clip.

14. All battery cables must be clean and tight for maximum current transfer. Check the cables going from the Negative(-) battery terminal/post to the engine mounting bolt

15. Also the one going from the Positive(+) terminal to the starter solenoid and from there to the starter motor.

16. If any battery cable feels ”Crunchy” when flexed, replace it as possible corrosion is inside the insulation. Inspect all heavy duty battery cables and the smaller wire terminations(Bullet Connectors), for failed crimps, and those used in the electrical connectors, as they can fail over time.

17. Each "Bullet Connector" will have to be sprayed to ensure good connectivity, especially the ones going to the energizing coil of the starter solenoid.

18. The alternator output “Bullet Connectors” are usually behind the engine sprocket cover and will need inspecting and cleaning too.

20. The turn signal light sockets will benefit from a spritz from the contact cleaner along with the tail light/brake light socket.

21. Some brake light switches can be sprayed on the actuating rod, with the spray running down inside to the electrical contacts, others may be sealed requiring replacement if the switch is intermittent in operation.

22. Some people put the Di-Electric Grease on cleaned terminations/connectors, I don’t, as I’ve read/heard it can cause problems when it gets hot, actually insulating the connections, so the choice is yours to use or not.

I think I've covered about all of the electrical systems on the bike.........

“I spent a weekend going through every electrical connection and switch on the bike with a little scotchbrite pad and DeOxit - what a difference! Everything was brighter, gauge backlights, indicator lights, turn signals, I was getting a nicer spark, it fired up quicker, etc. Well worth my time. WELL worth it! “

From a forum member at www.kzrider.com

I installed a new horn already. Maybe the ground is not grounded and that is why it only beeps some of the time. It makes no difference if it is running or not. I went through some of the electrical connections the other day and they really werent too bad, but I will go through the rest soon.

Thanks!

The horn switch is your ground, you may have a bad ground into it, corrosion in the switch itself or a bad ground to the horn, also there should be full battery voltage on the brown wire.

Underneath the seat, there should be a red wire and a blue wire from the Tail/Brake Light.

The red wire provides current to the rear bulb's tail light filament.

The blue wire provides current to the rear bulb's brake light filament.

The red wire connects to a red harness wire via a bullet connector.

The blue wire connects to a blue harness wire via a bullet connector.

It's possible that the bullet connector in the red wire has failed, whereby current isn't being provided through the red wire to the the rear bulb's tail light filament.

While investigating condition of the bullet connector in the red wire, and while the connector is separated, would use a volt meter to assure that there's battery positive voltage present inside the bullet connector portion that's attached to the red harness wire when the tail light filament is supposed to be burning.

The objective is to assure current being furnished from the harness red wire through the bullet connector and on toward the Tail/Brake Light.

With known current going through the red wire toward the Tail/Brake Light, and the known good tail light filament still not burning, it's possible that the red wire's connection in the bulb socket has failed. Or possibly an internal break inside the red wire somewhere between the bullet connector and the red wire's connection in the bulb socket.

Good Fortune!