Head light and horn not working on 1981 KZ750

I've been having problems with my head light and horn not working on my bike. I'm terrible with electrical troubleshooting, and before I go digging around the bike I thought I'd post here and see if anyone has had / knows how to fix these issues.

The first thing I did was to replace all of the fuses and sand the connections in the fuse box. No dice.

The head light was working when I got the bike, although I noticed it was flickering a bit and now doesn't work at all. A new bulb has been installed, but it still isn't working. The gas tank is currently removed so I can't start the bike yet, but shouldn't the headlamp light up when the accessory switch is on?

The horn has never worked. I also noticed there are two horns on the bike... can these be replaced with just one?

I need both of these fixed before the bike can pass inspection

word of the day TEST LIGHT its so easy or multimeter electric is like water it flows but you need a way to see it .if you have power going in a switch and none coming out something wrong with switch clean it replace it whatever. :huh: i dont know what is wrong with yours i would just be guessing at this point.

One way I've tested horns in the past is to run wires from the horn (disconnecting anything else that was there) and briefly touching the leads to a 12V battery. If the horn is still good, it should honk.

aftre u make sure the horn and light works.
a good place to start would be to take apart every electrical connection on the bike that u can find, 1 at a time. clean them and put them back together. i like ti rub the male ends with a 3m pad or a nail file. (dont take that the wrong way.). I have a small thin round (get your mind out of the gutter. Lol ) file that I use for the female ends. U may need to take the switches apart and clean the contacts as well. Be careful of small flying springs and bearings though.

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. 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.

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.

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've been cleaning up switches and connections. The horn now works after replacing it.



Above are two aftermarket ones the PO installed using the connector in the picture. You might be able to see in the picture that one of the horns are melted - wonder why that wasn't working. Replaced the 2 horns with 1 12v motorcycle horn.

Still working through to try and fix the headlamp, and I noticed something weird.

When the cable from the fuse box to the reserve lighting unit is unplugged, lights come up fine with the exception of the headlamp. When it is plugged in, the headlamp works but is very dim and eventually all lights, including the headlamp, will lower in brightness until they are dead. There are no issues with the battery. Is it possible the reserve lighting unit is bad?