Car Stereos: 2007 Silverado Front Speakers Quit Working, variable ac voltage, ac volts

Question
Hi Brian,

My two front door speakers just stopped working suddenly.  The two small speakers in the pillars still work.  The driver door speaker had been cutting in and out for about a week prior to them both going dead.  I pulled the stereo out of the dash and the connections in the back were fine.  I also wiggled the wires and didn't get any change.  The fuses for the stereo (per the manual) looked fine as well.

Thanks for the help.

Answer
Hi Steve,

It may seem odd, in a relatively new truck, but the most likely explanation is that the speakers have failed.  I don't know if you have the new body style or the Classic, or whether your truck is equipped with a Bose audio system; but in all cases, the front door speakers and front tweeters are driven from the same outputs at the head unit or amplifier.  This means that if the tweeters are working, then the amplifier or head unit outputs are working properly; the trouble would have to be either with the wiring running into the doors, or with the speakers themselves.

If you have a multimeter available with an AC voltage feature, you can test the speaker wiring directly.  Connect the black probe to chassis metal, set the meter for AC volts, and touch the red probe to either speaker terminal.  You should see a variable AC voltage on the meter, increasing as you turn up the volume on the head unit.  If voltage is present, but no sound, then the speaker needs to be replaced; if you don't see any voltage, then there's likely to be a break in the speaker wire at some point--most likely in the door to body conduit.  

Hope this helps!

Brian