Hi, all this is my first post. I have just bought a yamaha dt lc mk3 1987 but the last lights dont work. It has just passed its mot with its last owner, but the headlight and tail work when the bike is lOcked, park mode I think. Any help will be appreciated. Thanks

Also the horn works and kill switch, aswell as the rear brake. Thanks

If I were you I would check the earth connectors and the light switch itself might just be a simple broken wire or bad earth. The other thing you can do is clean the contacts at the fuses just to make sure they are clean and not shorting out when they come under load. That's what I would check first anyway.

PS if it all works when it's locked then look at the ignition switch connectors as well they might be buggered.