TESTING

If a speaker in the vehicle will not work, a small battery can be used to determine if the speaker has failed, or if the problem is in the radio itself or in the speaker wiring. Proceed with the following steps to test a speaker.

1. Remove the speaker from the vehicle. Refer to the appropriate procedure in this section for speaker removal and installation. When removed, place the speaker face down on a clean flat surface.
2. Purchase a AA or AAA-size (1.5V) battery and solder a length wire to both the positive and negative side of the battery.
3. Strip ¹⁄₂ –1 in. (1–2cm) of insulation off the ends of each wire.
4. To test the speaker, touch 1 end of each wire attached to the battery to each terminal of the speaker. If the speaker is functioning correctly, you will hear a crackling sound from the speaker when the battery makes contact with the speaker terminals. A dead speaker will make no sound when touched with the battery. Replace a dead speaker. If after testing the speaker and learning that it does function correctly, there is a problem with either the speaker wiring or the radio.

   A battery can also be used to check the polarity of a speaker. Each speaker has a positive side and a negative side, which are needed to produce the sound you hear when playing the radio. Even though a speaker will function if the positive and negative wires are reversed, the sound will not be as loud or as clear compared to when they are installed correctly. To determine the polarity of the speaker terminals, touch the wires of the battery to the speaker and watch the cone of the speaker as contact is made. With the speaker face down, if the cone moves towards you when the wires touch the speaker terminals, the positive and negative side of the battery are contacting the opposite terminals on the speaker. Reverse the wires and try again. A properly polarized speaker will move the cone away from you when touched with the battery.

   Although this procedure is not as important with speakers that have their respective terminals marked with a plus (+) or a minus (-), many factory speakers do not identify the individual terminals or wires attached to them. This procedure will be most helpful when installing aftermarket speakers into a vehicle using the factory wire harness.