Hello everyone.

So i have a 05 Impala 9C1 Base version, meaning i have the cassette version head unit. But it was ok, since a set up an adapter for the unit to accept iPod/Aux inputs.

Few weeks ago, in one of those rare occasions where I was listening to the radio, it just went dead on me, or so i though... What really happened is that the sound was very-very low, i have to put the sound bar to max so I can barely hear anything. The radio do tune to the stations but the sound it's extremely slow! and the condition only affects the FM band, AM band sound ok, so are iPod/Aux inputs, they both sound good. Only FM band doesn't.

I've already checked/replace the antenna module, who's integrated to the rear windshield and although when manipulating the module the sound somehow start to come out it ends up with no change at all. The car has no Bose audio system, so no amp in the trunk to check.

So what do you guys think?! I haven't try any aftermarket antenna; I had one laying around, but the connector wasn't right. Whats the spec on the diameter of the antenna connector in the back of the head unit?!

 

So... No replies?!
Anyone!?

 

As a test, what happens if you disconnect the adapter and bring it back to factory. Does the volume return to normal?

 

Yeah, that's one of the first things i tried... with no luck at all.
Besides... it really passed a lot of time, couple of months, with the adapter connected and I saw no signs of failure...

What's bothering me is that why only FM is going bad... why not the entire unit sound... i mean, in AM band and both inputs (iPod/Aux) of the adapter the sound is normal.
That's what leading me to believe its something else besides the entire head unit that's failing...

Or what do you guys think?!