68 horn and turn signals stopped working

On a ’68, you’re on the right track — the horn and turn signals both pick up their feed from the same fuse circuit. They don’t actually get their power through the headlight switch, but the diagrams make it look that way because the power distribution bus is shown near it.


Here’s what you’ll want to check in order:


- Fuse panel: Look at the 15A “Turn/Back-up/Horn” fuse. If that’s blown, neither the turn signals nor the horn will work.

- Power at the fuse: With the key on, you should have battery voltage on both sides of that fuse. If you only have voltage on one side, the fuse is open. If you have no power on either side, trace back to the ignition switch feed.

-Turn signal flasher: The round canister on the fuse panel. If it’s unplugged or dead, the turn signals won’t function, though the horn still should.

-Horn relay: Mounted near the driver’s side headlight bucket on the radiator support. Make sure it has power in and a good ground from the horn button.

-Grounds: Both the horn itself and the turn signal lamps need clean grounds at the radiator support and body. Rusty or loose grounds can kill both systems at once.



Since both systems quit at the same time, 9 times out of 10 it’s the fuse or the feed wire to that fuse or a short to ground after. Start there with a test light or multimeter.