Headlight help

my headlight doesnt come on. when i turn on the light switch, the left blinker lights up and stays on, but no headlight. i tested the bulb, its good. checked and cleaned a bunch of connections all over the bike. what am i missing?

Year and model of your bike is needed to help out. You can go into your profile and add the bike info to your signature for better results.
Now the head light is on a different fuse circuit on the later models. So this is one reason for the info. Have you a test light or meter? Can you test to see if you have power to either the low or high beam wire at the head light? The Black/ yellow is the ground, which also needs connection or no light.
the "File Base" at the Top Right corner of the KZR page will have a wiring diagram for your bike most likely.

Color Codes On Most Kawasaki’s (written for 1980’s bikes)

HEADLIGHT
RED with BLACK stripe, High Beam.
RED with YELLOW stripe, Low Beam.
BLACK with YELLOW stripe, the ground circuit.

BRAKE/TAIL LIGHT Can be an # 1157 dual filament bulb
RED, Running or Tail Light.
BLUE,(sometimes with a Red stripe) Brake Light Circuit.
BLACK with YELLOW stripe, the ground circuit.

LEFT FRONT TURN SIGNAL Can be an #1157 dual filament bulb
GREEN, Left front turn signal circuit.
BLUE, Left front running light circuit.
BLACK with YELLOW stripe, the ground circuit.

RIGHT FRONT TURN SIGNAL Can be an # 1157 dual filament bulb
GREY, Right front turn signal circuit.
BLUE, Right front running light circuit.
BLACK with YELLOW stripe, the ground circuit.

LEFT REAR TURN SIGNAL Can be an #1156 single filament bulb
GREEN, Left rear turn signal circuit.
BLACK with YELLOW stripe, the ground circuit.

RIGHT REAR TURN SIGNAL Can be an #1156 single filament bulb
GREY, Right rear turn signal circuit.
BLACK with YELLOW stripe, the ground circuit.

If your bike has the"Reserve Lighting System", it may have failed. The small module has a small 6 pin connector and plugs into a mating connector coming out of the harness.

oh yeah, bike model might help huh? lol its a 78 kz650 c2. and i do have a multimeter, just not sure how to use or what setting to set it at.

When measuring voltage for your bike, put the meter selection switch in VDC (Volts, Direct Current)
range of 20. Plug in the test probes; the Black one goes in the Black common (or Com)socket, and the Red probe in the Red V(Voltage) socket.

When testing for voltage, put the Red probe on the connector,socket, or fuse to be checked. The Black probe can go to either a good chassis ground or the Negative(-) battery terminal.

You headlight socket that fits on the back of the bulb has three(3)wires,BLACK with YELLOW stripe is ground,and the other two(2) have the high and low beam circuit. If no voltage shown, it's time to find out why. Does your left handlebar switch pod have a high and low setting? You might have to open this up to see if a bad solder joint or dirty contacts are causing this problem.

Ask if you need further help.......