That’s going to depend on the specific relay
There are many manufacturers and variants
Without more data all we can suggest is anecdotal experience.
Since it’s not expensive to fail, try it and see
Worst case it burns out or gets stuck on right?
I thought that there shouldn’t be a relay for the horn on that year so you won’t be risking an original part anyway
One of my trucks is operating the 6v horn on 12 v directly to the horn switch in the steering wheel, I don’t use it much, but it’s lasted that way since the previous owner converted it many years ago
-s
