Hello,

I recently added an aftermarket headunit to an 05 non-bose audio system. I currently have a Sony monitor (XAV-7W) and a Sony headunit (CDX-MP80) hooked up. I use the headunit as my primary and attached the monitor into the AUX input on the headunit. The speakers are powered by my headunit and the car wiring is all connected to the headunit. On the monitor, only the 12V constant, acc power, and ground is connected in parallel to the headunit.

All was working fine for a couple of weeks until yesterday. I am getting no sound to the speakers. I hear a thump noise when I turn on the cd player or radio, and it stays silent afterwards. Also, when I turn off the engine I hear a thump noise. Could you guys help me troubleshoot this? I don't think the non-bose speakers are amplified so I should not have issues with that. Please let me know what you think. Thanks!

 

do you only not have sounds when you are playing something with the monitor or all the time? what if you put a cd in?

 

There is no sound from the monitor or the headunit. Just complete silence except the thumping. I tried both the CD, radio, and monitor inputs.

 

It sounds like the head unit is going in to protection mode. This typically happens when one of the speakers is shorted out (either wiring issue or blown speaker). I would try disconnecting all the speakers from the head unit and connecting a known good speaker to one of the speaker outputs and see if that speaker works. If it does, then you know the head unit is good and that the problem has to be with one of the speakers or in the wiring.

If you connect a known, good speaker to a single speaker output with the other three disconnected and you get nothing then your head unit is most likely defective.