82' kz750n horn failure, then tachometer stops.

I have an 82' spectre, the stock dual horn, finally disintegrated and I tried replacing it with single 12v horn. ( horn this one ) and upon testing it. It worked once, then the second time it blew the 10a fuse, I replaced the fuse, the horn doesn't work and I've also lost the lights for the cluster and tach. is there another fuse inline normally?

Your new horn needs too much current, (Ampere), more then the 10 A fuse
let flow. You need a relay to switsh such a high current and don't try a
greater fuse!!! You can easily burn and molten your horn button.

I was thinking the same thing, but the KZ750N Spectre has two 2.5A horns, so wouldn't the current draw be the same as the new 5A horn?

JMKZHI wrote: I was thinking the same thing, but the KZ750N Spectre has two 2.5A horns, so wouldn't the current draw be the same as the new 5A horn?

That’s what I thought... that the two could be replaced by one. - should I just run a new line with fuse from the battery to the horn button directly?

The horn button activate the relay only.
The relay close the battery + to horn to ground -, (frame ) circuit.
Some relays have a blade fuse integrated.