QuestionQUESTION: I also have a 2002 Trailblazer with a Bose radio with CD player. The radio has become intermittent. Works in the mornings some times but stops working as the day gets hotter. The headphone jacks in the back seat work. The local radio shop thinks it is the amplifier that is located in the passenger side rear panel. To test I will have to buy a $500 amp which is not returnable. Had any other people with this problem? Radio shop person said it might also be a short in a speaker which causes the amp to go into a protect mode???????
ANSWER: Hi Bryan,
I've heard of temperature-related problems with Trailblazers in the past, but in those cases, the radio usually doesn't work in cold temperatures and starts to work again once the vehicle warms up. It sounds like you have the opposite problem. The cold temperature problem is not limited to Bose-equipped Trailblazers.
Unfortunately, I can't think of a foolproof way to determine for certain whether the amplifier is the cause of the problem. I'd probably try to do some testing with a multimeter first. You can verify power at the thick orange wire in the smaller plug at the amp; a loose fuse in the fuse box might be causing the amp's power to cut out. You can also test for a shorted speaker or shorted speaker wire, using the multimeter's resistance or continuity functions with the speaker outputs at the amplifier. You can use the AC voltage setting to verify that an audio signal is reaching the amplifier from the head unit.
It's possible that you can identify a different problem with the multimeter testing; but if you don't find another issue to address, then the only way to know for sure would be to install the new amp and see what happens.
Good luck!
Brian
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QUESTION: I have found that the back seat head phone jacks work all the time. I would guess that that elimanates a problem with the radio head. A local radio shop checked all the connections and they appeared to be OK. Everything still points to the amp. Thanks for your help and I hope my problem info will help someone else.
Bryan
AnswerBryan,
The Bose system in your Trailblazer is a bit unusual. The head unit produces a low-level, left and right output to supply the audio signal to the factory amplifier. The front/rear fader function is performed by the amplifier, controlled via data commands by the head unit. A separate pair of outputs from the head unit is connected to the rear seat headphone jacks. The fact that the headphone jacks work does suggest that the head unit isn't the problem, but it doesn't completely rule it out, because different outputs are used for the amplifier and the rear seat panel.
You can get detailed wiring information for your Trailblazer's audio system, including the wire colors and pin positions at the head unit and amplifier, buy searching Crutchfield's support files at this link:
http://www.crutchfield.com/App/Support/SupportHelp.aspx
Hope this helps!
Brian
