I’m wiring up with a new harness and I’m having trouble getting the horn to honk. It’s a 12V system and the horn works when hooked up straight to a battery but not to the wiring harness

The lead on the harness to the horn is continuous positive.
From the relay(3 prong) one wire supplies power.
Second prong from relay has no power
Black wire from last prong is constant power and says to connect to horn on column.

Is this correct? I thought the column was negative. Also horn has a continuous positive?


Daniel
1949 Chevrolet 3600