1977 Tail light lost voltage Brake works fine

Kz1000A yes. Im going to have to try the ignition switch once more.

galaxian wrote: Now im getting 7 volts at the tail....not sure what to do about it yet. As far as pulling the pins they are in the pod where the key inserts.

Under the seat, there's likely a bullet connector between the red wire coming from the harness and the red wire going into the tail light. (Am thinking stock KZ1000-A1 wiring.)

If not already done, with both ignition and headlight switches turned ON, would measure voltage at the female half of the bullet connector (under the seat) that joins the red wire that feeds into the tail light.

Presupposing full battery voltage is present at the female end of the connector on the red wire from the harness, it's possible that the bullet connector is for whatever reason failing to conduct full voltage.

Possibly there's corrosion in the bullet connector that's preventing full conductivity.

Even with a prefect bullet connector (no corrosion and snug fit) , it's conceivable (1) that the red wire from the harness is frayed where it joins the female half of the connector, and thereby failing to conduct full voltage, and/or (2) that the red wire into the tail light is frayed where it joins the male half of the connector, and thereby failing to conduct full voltage.

Good Fortune!

After testing the ignition switch and plugs it turns out a broken wire at the fuse box. I installed a new blade type fuse box a while back and the wire got loose. Thanks to everyone for their help and suggestions.