TOPIC:

I have a 1980 kz440 A. Tail light went out. I replaced the bulb, didn't work. I can't imagine what else it would be. Any help would be appreciated.

Check the fuses, you probably have one for the tail light system like I do.

Have a test light? Turn ign on and see if you have power, if so try "another" bulb. I've seen new ones not work. If no power do as OKC_Kent says. Let us know...

Lack of info on the problem makes diagnosis harder... do you mean both the brake lights and running light fail to work? While you only have one tail lamp assembly, and one bulb (OK maybe two), there are two separate circuits involved... the red circuit and the blue circuit. The red is the running light and blue the brake light. They run off separate fuses. You can see that if both are out, this implies it isn't a fuse problem. If this is the case, open your seat and look at the connector that connects the main harness to the small sub-harness that connects to the tail lamp and rear blinkers... it will likely be loose. It could also be that the ground is loose or broken for the tail lamp as both the red and blue sub circuits which connect to the light bulb holders share a common ground (black/yellow). If only one of the tail lamp functions are out; either the brake light or running lamp, the diagnosing will be far different... fuses and connectors working up to the ignition switch with the blue going through the brake light switches will need to be checked.

Thanks for all the help. I replaced the fuses, it still didn't work (though from their looks needed replacement), then I traced the wire to a faulty connection (under the seat, amazing!). Works great now.

I have a similar problem. I keep blowing tail light fuses. I recently replaced a fuse and the tail light didn't come on right away. A couple taps with a finger directly on the tail light lens and its shining bright. Down the road I go only to find at the next stop the tail light isn't working again. The brake light works fine by the way. So I am assuming the problem is in the tail light wiring and not the instrument wiring (same fuse). So, I removed the light and unplugged it completely thinking that if there's a short somewhere it wouldn't short out being removed. I put a new fuse in and it blow almost instantly. Where should I go from here?!?