Hey everyone, I'm Mike. Im new to this forum. Im sure this has been answered before, but Ive researched over and over and haven't seem to find the right answer. I have a 2004 G35 Coupe (MT) with a Bose system. I recently bought the car, and every now and then the speakers would shut off and then THUMP back on, as if the the subwoofer was going in and then back out. And unlike some other posts I've read, it was ALL the speakers, not just one side or back/front. It felt like it was doing it while I switching gears (maybe just seemed that way), then finally it just went out and wouldn't go back on . EVERYTHING on the dash/radio works, AC, all the controls, shows the stations, even the "mode" button makes noise through the speakers when i click it. I have checked all the fuses, took out my friends Bose AMP from his 350Z which has the EXACT same connections, and still nothing. There are two plugs to the back of the AMP; a white one with about 6 prongs and a black one with about 10-12. From checking my plugs and then comparing to his (350Z), it seems that both of our white plugs have power BUT my black plug has absolutely no power coming from it, unlike his the black plug has constant power from the top set of prongs. I've ripped the whole dash out to get to the radio, and everything behind there seems fine . I know the head unit is a common problem, but usually other things go wrong such as the CD getting stuck, AC getting stuck or nothing showing, but everything works on mine perfectly fine. Im starting to think maybe something to do with the subs. I don't want to rush and end up spending extra money for no reason, if anyone has any idea, any help would be really appreciated. Thanks for everyones time.

 

I bet it's a grounding problem with the amp. I think it partially grounds thru the mounting feet/bracket to the chassis, so take it apart and sand all the corrosion/dirt/etc. off of the interfaces.

I had a wierd problem with my aftermarket stereo and bose amp where one channel seemed like it was fading in and out. Greatly improved when I fixed the grounding.

 

I tried plugging in my amp to my friends 350Z without even completely taking out his amp and just holding my amp in the hands and it worked fine. I also don't have power coming from the black plug itself on my car. I'm starting to think its the head unit. Thanks for your help.

 

Hey Mike, If your friend is cool I'd suggest parking side by side. Put your amp back into your car and install everything back to normal. Power ON both cars and test voltages on both cars and see where you're losing power.

Eric makes a good point about the Ground connection, make sure it's clean and tight. I have schematics if your interested, just send me a pm.

From how you explain things it does sound that the head unit is failing, but confirm voltages or borrow your friends head unit.

Good luck!

 

PM sent.
Thanks for the help.

 

Hey Mike, so here's the deal. The white plug contains your power/Ground connections. Your black plug contains inputs from your head unit and outputs to your speakers. If your amp works in your friends car it sounds like you’re getting no output from your head unit. I suggest borrowing your buddy’s head unit to test in your car or replace your head unit. It’s not long before your CDs get stuck and so on and so forth.

 

That's what I'm figuring it is. I traced those wires back to the head unit and the plugs that go into it. If I provide power to the baby blue wire and another white wire in two of the plugs it initiates my speakers. So as I assumed and as you stated its most likely the head unit not providing feedback to the speakers. I have a guy who works on these who can take a look at it Friday or Saturday and hopefully repair it. I appreciate all the help.

 

Oh very cool, stuff like that can be cold solder joints on the circuit board or some bad caps. Its certainly repairable, good luck!

 

Some good points here... If the amp isn't getting power try hooking up an external line from the battery like you would for an after market amp.

If you go with aftermarket head unit, replace the amp in the rear too and run all new lines or get a line booster.

The bose amp requires a line booster or you won't get any gain into the amp (probably a wierd bose input impedance thing).

 

Thanks for everyones help.
It was the head unit after all.
Got a used one from a local Junk for $145.

 

hey im having troubles with this too can you explain what I’m supposed to do

 

Well his problem was his stereo (head unit).

Do u get any sound outta yours?