Horn speedometer and left turn signals do not work.

You most likely have a ground short either in the handlebar controls (this is the most common culprit) or inside the headlight (that’s where all of the handlebar wiring is joined before it passes down the backbone.) If those two locations don’t reveal the culprit, you’ll need to chase the ground short which is a slow and tedious process. Anywhere there is exposed wiring could be the location.

Maybe one of the guys on the forum can share their technique for chasing ground shorts. I’ve always had to take my vehicles to an old-school auto electrician as my electrical troubleshooting technique is hunt and peck.