QuestionThe radio worked and then sound periodically would go off and on. Recently, it started to go out for a few days and then back on. During this time, a pop sound comes out of the speakers occasionally. Now the sound has been out for several days and it will make the pop sound. I purchased this vehicle used, and found the rear speakers, I want to say don't work or sounded muffled from the beginning. I was told to get a new radio, but I suspect something else is going on. During all of this the radio marquee continues to work. Thank you for your time and help with this.
AnswerHi Rosemary,
Sorry about the delay in answering your question.
I'm assuming that the audio system in your vehicle is all stock, and not after-market replacements. If so, there are a few possibilities, depending in part on the type of factory audio system you have. If your Tahoe is equipped with a "Bose" audio system, then there's a factory amplifier, located below the center console storage compartment, that drives all the speakers. If you don't have the Bose option, then the amplifier is built into the radio unit.
I doubt that all your speakers are defective, so if you're not hearing any audio at all, then it's because the amplifier isn't producing sound. There are two possible causes for this.
First, the radio or amplifier may be defective.
Second, a problem with a speaker or speaker wire may be causing the amplifier to shut down for protection. A short circuit on a speaker wire or inside the speaker can cause an overload on the amplifier, but most modern car audio systems have a protective circuit that will cut off the output to all the speakers if it senses an overload.
When I'm troubleshooting a problem like this, I start by unplugging the radio or the factory amp, and using a multimeter's resistance or continuity function to test each of the speaker wires. I'm looking for a speaker wire that shows continuity to chassis ground, meaning the wire is pinched or shorted somewhere in the vehicle. I'm also testing the resistance between the positive and negative wire of each speaker pair, looking for a resistance lower than about 3 ohms--this indicates an internal short in the speaker.
The "pop" that you're hearing tends to indicate a problem with the speakers or speaker wiring, rather than a defect in the radio or amplifier. If you can isolate the problem to a particular speaker, then disconnecting that speaker may get the audio working in the rest of the system. If the pop always seems to be coming from the same speaker, that might be a clue.
My best guess is that a defective speaker is causing your problem, and replacing or disconnecting that speaker will get your system working again.
Hope this helps!
Brian
