Car Stereos: speakers, internal amplifier, blown fuses

Question
i hooked up an amp for one sub that is running off of it only the other speakers dont give out any sound at all  there are no blown fuses and there is still power to amp sub and head unit.

Answer
Hi Travis,

Sorry about the delay in answering this question.  If I'm understanding you correctly, your subwoofer is working but the front and rear speakers are not.  Are these speakers connected to an amplifier, or directly to a head unit?

When a head unit is powered up, but doesn't produce sound, there are a couple of likely causes.  First of all, if the vehicle is equipped with a factory amplifier, you might need to make an extra connection to activate the amp before the speakers will make sound.  Usually this is done by connecting an activation wire in the factory radio harness (just like the "remote" wire that's connected to the after-market amp).  I'd need to know the year and model of your vehicle to tell you whether a factory amplifier is likely.

The sound can also be cut off if you have a shorted speaker wire (or a speaker with a shorted voice coil).  In this case, the head unit's internal amplifier will shut down for protection.  It can be caused by a speaker wire that's pinched or grounded against chassis metal, a loose connection at a speaker, or a defective speaker.

Hope this helps!

Brian