Could well be your clock-spring is broken... also known as the spiral wound cable. As your steering wheel turns there is a flat ribbon cable attaching all the buttons on the wheel to the steering column that winds/unwinds as you turn. It breaks eventually.. a known issue with Toyota. If it also breaks the connection to the air bag Toyota will replace it.. other than that you are on your own.. to the tune of $560 Canadian for me.
I had no horn if the wheel was straight ahead.. turning the steering wheel a 1/4 turn either way and I had a horn.. your mileage may differ.

 

What is a S-horn fuse?

 

Security system horn fuse.

 

it turned out to be the clock spring fault.

 

Did you have any luck with Toyota paying for it?

 

no i don't think it is still under warranty

 

Spiral cable needs replacing 2013 Highlander. Today’s quote, 6/14/24 from Toyota dealer is $1021. More than 10% the value of the vehicle

 

Thanks, can anyone tell me what else other than the horn would fail to work if the cable was at fault..? Seems a good way to troublshoot the issue. Tanhks in advance!

 

Test the horns directly ands see if they're working also if they're getting power. I don't see you doing any diagnostics.