Headlight Problem

Last night at 10 o'clock I was out visiting. I left and hopped on my bike and no headlight. :huh:

No high beam or low beam. All the other lights are working fine. The instrument lights are on. I'm not a wiring guy and really have no idea where to start. I have the headlight out but if both high and low beam are not working - what are the chances of that? How do I find the problem? Is there a fuse that may have blown?

I can do most other things but I am not an electrics guy.

Also, if I have to change the headlight does anyone recommend a good light? A strong halogen or maybe one of those European headlights with the blue tinge?

Oh yeah, the bike is a 1984 KZ750 L4.

Thanks in advance!

check to see if you are getting power to the head light, could be a s simple as a loose connection in the connector, should be a three wire connector, high, low and ground

Could also be that the light itself is burnt out.. ?

Oh..and the Sylvania superbright ones are pretty damn good. When I have to replace my bulb I'll be getting one of those. My wife complains about how bright my light is now (when driving in front of me)..wait til I change it! :laugh:

www.sylvania.com/ConsumerProducts/Automo...formance/Silverstar/

Post edited by: pyxen, at: 2007/05/09 09:05

It isn't likely that both the high and low beam burn out at the same time. If they both go, your reg/rec is likely shot. You will need to do some troubleshooting. You can pull the bulb and check to see if they are burned.

The way your headlight works is that power comes off the main fuse via the ignition switch and comes out on a BLUE circuit. To see if the specific fuse for the blue circuit is blown, just start the bike and press the brake pedal or pull the brake lever. The same blue circuit powers the BRAKE LIGHT (not the running light but the light that comes on when you apply the brake). If you have no brakelight, check the fuse for this circuit. If the brakelight works, here is how the headlight works:

From main fuse through ignition switch; when in ON position, power comes out a blue wire. This blue wire goes to the left switch gear and provides a HOT for a two pole switch. One pole has a red/yellow wire and the other a red/black wire. These are the HOT wires for the headlight and they run to the headlight shell. One is the hi beam and the other a lo beam hot. In the shell they go into a three prong connector that also has a black/yellow ground for the bulb holder. The connector connects to the headlight via a small harness.

If your brake light is on, use a test light (they cost less than $5 at the autopart store). Open left switchgear, start your bike, and put the clip for the ground on a ground and the probe on the solder joint where the blue wire hooks into the hi/low switch. If you have 12VDC, the fuse and ignition switch and wiring are OK to this point. Put the hi-beam on and check the terminal where the hi beam wire is soldered... I think it is the red/black (could be the red/yellow?)... anyway, check it and then put the switch in the other position and check for voltage there as well. If the switch is OK, then open your headlight shell and repeat the voltage check at the other end of the wire after undoing the connector. At this point, if your light comes on for both the high and low beam, your problem is with the bulb or bulb holder if the headlight doesn't light. Check the connection; this headlight connector is sometimes melted/burned from heat.

Thanks everyone. And thanks wiregeorge. I'm printing off your instructions to use tonight.

My headlight is a 100 Watt High Beam halogen. Is that decent? Are their stronger ones available? I figure when you're riding a bike the more visibility the better.

100w highbeam divided by 12 VDC = 8.3 amps loading the headlight circuit. The headlight circuit 10A fused? If so, you are cutting it fine... the little 18 gauge wire and connectors weren't designed for that much current and I suspect excess heat will eventually kill the circuit. The headlight isn't the only thing on the circuit... the brake light is too!

You might want to consider one of the super white 65/55 type bulbs. I use those Sylvania bulbs someone else already suggested in a couple of my bikes just for this reason. If you notice, in the headlight shell, the black connector that connects the headlight and the connector that brings in voltage for the headlight (other end) are usually half melted on many bikes... Also, the way most KZs are wired, the main fuse will generally blow before the 10A sub circuit fuses so the wiring and connectors get beat up instead of fuses blowing.

Strange - headlight didn't work, brake lights worked. Found a burnt fuse and replaced it. It was so fried it crumbled in my hand.

I bought one of the lights you suggested wiredgeorge. It's a Silverstar pyxen. Very nice light! Everything is great now!

Thanks for your help.

Post edited by: Lock2Lock, at: 2007/05/09 19:48