Hooking a 24v military horn up - what connects where?

Am about to install a military 24v horn on my truck, the two lines in are stamped with ID for the wiring harness, but the horn has no markings showing positive or negative, A or B, nothing. Is there a difference which wire I plug in where on these horns?

The horn "coil" like a relay coil is not effected by polarity. So connect one wire to 28 volts and run the second to the horn button to be grounded when operated. Both wires may be marked "25", although one of wires on the electrical horn on my 8x8 was marked "25A" (the other is missing).