How to Distinguish Positive and Negative Terminals of Car Horn Wires?

[EmmettMarie]

Select the range and setting of the polarity tester based on the horn's power and voltage. Connect the test leads, power up the polarity tester, and turn on the polarity tester switch. Touch the test leads to the two input terminals of the horn (speaker). The horn will emit intermittent beeping sounds. Align the horn towards the microphone of the polarity tester. The indicator lights will illuminate: green indicates positive, and red indicates negative. If the result is positive, the terminal touched by the positive test lead is the positive terminal, and vice versa for the negative terminal. If a single horn is used for listening to music, the polarity of the horn has no effect.