Alpine XM head unit. Boston speakers.

The head unit still gets power and displays everything. There is no sound however.

As soon as the unit gets power(whether its replacing the face plate or turning the car on with the face plate already attached) there is a mild almost pop or slight short crackleish noise from only the driver side rear speaker. No sound coming from the speakers but everything else appears to work.

Connections seem fine, fuse is fine.

Help? Not versed in car audio troubleshooting

And for what its worth, the car has gotten rain a couple times this week whereas it normally doesnt see rain. But I cant imagine thats the problem..

Help please, will trade for detailing info!
Thanks very much in advance

 

when did it stop producing power?

 

What do you mean stop producing power?

I can put it this way: the radio worked the last time I drove my car. Yesterday I went out to give it a quick vaccum and noticed the headunit would light up and display, but as soon as the HU got power(like when I put the faceplate back on with the ignition already turned) there was a single pop noise and nothing else. The pop happens each time.

 

It sounds like one of your speakers is grounding out. I would pull the speaker leads on the speaker that pops (the one that pops is usually the one grounding out) and see if your audio comes back.

 

Ill give that a shot. what would cause it to ground out?

And whats my next step in case thats not it?

 

I meant producing sound when I said producing power. Sounds like a grounded/shorted speaker lead to me too. Or the headunit just up and fried.

 

It could be almost anything that could of caused it, unfortunately I dont really know off hand what to look at next. If unplugging the popping speaker doesnt fix it then i would look into testing the speaker leads with a multimeter and seeing if any of the other speakers are grounding out. There could be several variables that could come into play. If I could look at in person it would be a different story....
Modern day headunits will shut off the internal amp when a speaker is grounding out or going bad just to protect itself.


Let me know if that fixes it.

 

The headunit works though? It displays just fine, fans come on, do you mean just the part that goes to the speakers?

Im gonna go check the speaker wires again I guess, at least the rears...ill post back in a few

 

Yes, just the internal amp portion, or like Xraycat said, it's cutting out the amp off to protect itself.

 

If it is in fact the lead, what would be the next step to fixing it? Just a new wire and respective connections?

And actually, what could have caused something like this? It was working when I turned the vehicle off..

 

I've seen speaker wires catch on power windows and get ripped out when the windows were rolled down. The wire may have broke where it bends at the door hinge. A connection could have vibrated off. Anything's possible.

 

Well, great news!

I have figured out a thing yet . Speaker leads were pulled, with no improvement. The noise was absent on power up first couple times after checking the affected, but now sounds like a quick slight hissish noise.

What should my next step be? Im kinda disappointed though im more than happy to listen to the motor instead, i just need some tunes.

THanks for the help so far, whats next?

 

Test the speaker leads with a voltmeter (AC voltage setting) while playing a cd with the volume fairly high. It would be best if you had a cd that played test tones so the voltage will be constant instead of changing with the music. It doesn't sound like you'll get anything, but it's worth a shot. You should check it by unplugging the harness adapter behind the headunit if you have one. You can also read the speaker leads with the ohmmeter setting to see if they're shorted together somewhere.

 

Update:

The hissy cd track change sound comes when the last source is Disc and the faceplate is replaced , and the pop noise comes when XM is the source and its replaced



Biggie: I dont have a meter. What should I look/listen for if I unplug the harness in back? Is there anything I can do at the XM receiver level? Its separate location from the HU

thanks much so far

I think what annoys me so much is that I didnt do anything to it..

 

Without a meter, there's not much you can do with the harness in back. You might try unplugging the xm receiver from the headunit and see if that changes anything.

The one other time I heard a hissing noise during cd track changes it was a either a bad ground, or the headunit was toast. Sorry I can't remember, it was probably 12 years ago.

You should be able to get a meter from walmart or radioshack for like 10 bucks.