[rotorwrench]

I don't know about the pre-war vehicles but later Horn relays are marked with single letter characters at each terminal. S for switch, B for battery, and H for horn. This makes it less confusing to hook them up unless the wires have lost their color. Then it can be confusing no matter what you do.

A person may want to try and pull that horn wire up out of the steering shaft and see if it has worn insulation that could cause a short. Even an intermittent short could cause some heat. In any case, a good inspection of that circuit wouldn't hurt anything.