Car Stereos: 2004 Trailblazer rear speaker, chevy trailblazer, 2004 chevy trailblazer

Question
Hi Justin-

I have a 2004 Chevy Trailblazer LT with a factory 6-disc CD changer  A while back the right rear speaker went out. (Fade to right rear = no sound).  Had to aftermarket speakers installed (JVC drvn 6-inch) and had great sound for about 2 weeks.  Then I noticed the left rear speaker started to fail to provide the bass it was previously supplying.  Sometimes it works, sometimes it doesn't.  I'm told that this a problem with the master stereo unit involving the channels to the speakers.  Have had not problems in past with radio.  

Wondering what your thoughts are???

(Would prefer to avoid having another stereo/CD unit installed.)

Answer
Hi Jim,

The first, and easiest thing to do to test is to swap the speakers.  If the sound issue follows the speaker, you know it's the speaker that's gone wrong.

If you have a multimeter, you can test the signal to the wires going to the speaker.  There should be NO continuity to ground on either of them, and there should be no continuity between the wires themselves.

There should be 1ohm or less resistance from each end of each wire.

If all that checks out, unfortunately, you're looking at headunit replacement.

Justin