TOPIC:

Hi everyone. I am new to the forum, to the bike world, and to the kz650. I just bought a 78 and the high beam, doesn't work. I bought a replacement bulb thinking that, it was just burned out. That doesn't seem to be the case. So does anybody have any suggestions? Keep in mind I am such a noob. But I have already spent to much to raise it from the dead. So any suggestions would be greatly appreciated.

Thanks so much
Kcam1999

More than likely,the headlight plug,inside the headlight bucket.Probably corroded or loose.
Take a look at the wires while you're in there,as it could be that too.
The high-beam switch...how does it feel when you click it to high...is it sloppy? switch might be worn out.

No the switch is tight is tight. I will have to check the corrosion. The low beam works just fine. When I switch from the low beam, to the high, it just turns off. When I switch it to low it goes back on. Thanks
Kcam1999

Does the high beam (a little blue light in the instrument cluster) go on indicating high beam? A broken wire is another possibilty along with corrosion of the bulb socket.

Get a multi-meter and check the voltage at the socket as it should change from one to the other when high beam is selected. If not check further up the wiring harness for dis-connected wires.

The connector for the headlight has three prongs one is ground and the others are hi and lo beams.

crazy to think, but, some one might have said, "I don't use high beam anyway so if I cut this wire it would make my high beam an off switch for my headlight...blah blah blah."

If you have an meter check for voltage at the head light plug. If you don't have a meter, a lightbulb tester can be picked up pretty cheap.
www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=4288

at that store you can get a meter cheap too, but I don't know how good they are.

If no power at the socket check just after the switch. From there you will know which way to trace.

Even a tight switch can get enough junk in it to not function properly so I wouldn't rule that out.

Most of us own a multimeter which will work fine for tracing the problem but you can also use a test light which is even cheaper and easier to use. It is essentially a 12VDC light bulb with wires attached. OK... the power for your headlight comes from the ignition switch on a 78. It comes into the left switch gear and connects to a two position switch. One position is high beam and one position low beam.

First, take the test light and connect the ground to a bolt. Then take the probe on the light (sharp metal part) and with the key ON, touch the wire that comes into the switch from the ignition switch. I think it is MED BLUE. I could be wrong as I am old and my memory bad. The light should light because you have power coming to the hi/lo switch if the low beam lights. If you get no light, you need to figure out why as there IS power to this point. Next step is to put the hi/lo switch on LOW BEAM and put your probe on the low beam contact. This will be connected with a RED/YELLOW wire I believe. You should have the light come on here too since power is obviously getting to the bulb low beam. (this is with key on)

Next step is to put the switch into the HIGH BEAM position and probe the pole on the switch to see if you are getting electricity through here. If you don't, then the hi/lo switch is defective. Make sure you are touching the RED/BLACK wire coming off the pole... If you get power here, all is good to this point and your problem is downstream but if not, the switch is bad. You can try taking it out and replacing or cleaning the contacts and retesting.

If you did have power, note that there is a RED/YELLOW and RED/BLACK set of wires going through to the head light shell. These terminate in a big black connector. These connectors are often toast as they get a lot of resistance from oxidation and get hot and pretty much melt. This may be the case here. There will also be a ground wire coming into this connector. It is BLACK/YELLOW. Remove the plug for the head light. Use your test light again by grounding it using the wire and clip and putting the probe into the connectors inside the big black connector. First test low beam wire/connector by turning the key on with the switch in low beam. The test lamp will light since you have low beam. Now test the HIGH BEAM connector/wiring the same way. If it doesn't light, either the connector is oxidized or broken or the RED/BLACK wire is broken.

If you did get a light on the high beam connector, either the black/yellow ground is bad... they often get corroded... or the connector on the bulb side is corroded.

There ain't much more that can be done as you pretty much have to find the problem doing these steps.

Thank you so much everybody I will have to try this when I get my bike back. Its in the shop, the clutch cable broke when I was in the middle of nothing.
Thanks again so much
-Kcam1999

Just wanted to thank everybody for the help. After tracing the wires back and forth I found that one of the wires was corroded and so just cleaned it and I was set. Thanks again. I am now legally on the road.

Thanks
-Kcam1999