Car Stereos: no sound from my speakers!!, factory wiring harness, internal amplifier

Question
QUESTION: ok, heres some more info for ya:  I am not entirely sure what you mean by how did I install the new amp.  My husband actually did it, but I can tell you that it is mounted on my subs in my trunk, and it has the red wire going to my battery, the ground is hooked into my trunk wall and the blue wire is hooked up to the head unit.  The amp and subs work and I can hear bass and a little music from them.  I used an aftermarket deck.  it is a panasonic.  And the only way that my speakers are hooked up is through the factory wiring harness that goes into my new head unit.  If it helps to know this, I had cut the wires instead of getting an adapter thing for the new hu. (stupid I know)  And like I said, its just the cars stock speakers that are not working.  I dunno...

ANSWER: Hi Ashley,

Was the aftermarket deck installed before the amp, and tested and verified to be working before the amp/subs were installed?

If so, then ask your husband if the amplifiers were hooked up via RCA or speaker level inputs.  If its RCAs, then make sure that it's hooked up to the 'subwoofer out' RCAs on the deck and not the front/rear right/left as the deck may turn off the internal amplifier for those if it feels they aren't needed.

If they're speaker level, check the connections where he spliced in for the inputs and ensure that he didn't accidentally disconnect the factory speakers in the process.

Also, it might sound silly, but if he used RCAs on the correct hookup, check the volume, and l/r balance/fade on the deck, as subwoofer output is usually unaffected by those settings, and if they're turned down, then you might get the exact issue you're experiencing.  Also, if the aftermarket deck has any internal fuses of its own (tiny little fuses, often obscured by the harness plug), and make sure they've not blown.

Also, if the deck wasn't verified to be working with the factory speakers before the amps were installed, it could be a simple issue of the new harness having been installed wrong.  To find which wires go to the speakers, eliminate the 12V accessory, 12V constant, and ground wires from the factory wires, and then test the impedance of the remaining wires against one another with a multimeter.  When you find a speaker, you should get a reading of ~4ohms. Once you find a speaker, connect each end to a double-a battery and run your finger along the battery.  You should be able to hear static out the speaker that you've found.  Then mark the wires and hook them up.

Justin

---------- FOLLOW-UP ----------

QUESTION: no the deck wasnt installed before everything else...we just put everything in without testing it, cuz we had done this before and didnt think about it first...  however I did test the hu at the store before I bought it and IT works if that helps any...  the amp is hooked up via rca's.  I'm gonna go check those and the balance volume etc... right now... also I have kinda tried messing with the speaker wires and the double a battery but I cant seem to hear any sound at all.  and I dont have a multimeter either...   :(  can I do another test without one?  or maybe Im doing the battery thing wrong...  I have my constant, and acc, and ground right I think cuz my radio works... But actually I WAS wondering if maybe my ground wire and a speaker wire is hooked up backwards...is that possible without blowing up or something? because my harness from the car has 2 black wires coming from it and they are about the same thickness, but I was too scared to switch them and try it different.  what will that do? cuz I know one black is a ground and one is supposed to go to a speaker.

Answer
Hi Ashley,

It is very uncommon for factory systems without amplifiers to share a common ground, so if you'd simply misplaced one ground with a speaker ground, not only would the deck not turn on, but there would only be ONE speaker that wouldn't work, as opposed to all of them.

Based on your responses thus far, I'd be almost certain there's some swapped wires behind your deck.

I would suggest spending the $15/20, getting an aftermarket speaker harness from your local electronics/stereo shop, putting the factory harness back on, and then connecting the aftermarket harness to the deck harness.  It will save you a world of issues in the end, even if I'm completely wrong.

Justin