Bought a Tacoma - weird horn setup

The Tacoma I got has an air horn installed, with 2 wires, one grounded, one hanging out by the battery

works if I touch it to the battery, but it’s not connected to the steering wheel - is there a way this 2 wire setup can connect to the steering wheel? I’m not sure what id connect the end of the wire to.

 

You need a relay.

The horn switch is not robust enough to close the circuit to make the horn blow.

I'm guessing the previous owners abandoned the project not having the electrical know how to finish up the job.

 

Fused contacts on the relay the horn kept blowing cut wire to disconnect.

The Op should be able to use the stock horn relay if that was not removed.

The current needs of the after market horn should be known the horn circuit fuse may be to small.