Car Stereos: Aftermarket Stereo Installation, jeep grand cherokee, power hookups

Question
QUESTION: Hi Justin;   I installed a Nextar radio/cd player in my 1995 Jeep Grand Cherokee.  Followed wiring guidelines for speakers and power hookups.  Only mistake I made was a dandy as I cut the wires from the factory clips.  I did manage to figure out the system to connect the speaker wires.  The problem is I can't get any audio out of any of the speakers.  Radio shows that the antenna is working as a strong signal shows on local FM stations.  Just no sound.  I had previously wired the speakers differently (likely incorrectly) and the sound did come on for some time in the front speakers only.  It didn't come back after I hit the mute button.  While re-wiring (hopefully correctly) I did have static but then nothing.  I stopped at a local installer and one person there mentioned the Infinity Booster under the back seat may have something to do with this.    Can you help me out?

ANSWER: Hi Jim,

If you left enough gap and still have the factory clip, I'd suggest reattaching it (solder & electrical tape/heat shrink), and then buying an aftermarket harness.

If you've cut it too short, you're going to have to find which speaker wire is which the hard way.

To do this, start testing wires with a multimeter set to ~20V DC.  Touch the two ends to each lead off the multimeter.  If it reads 0, then switch the multimeter over to resistance/continuity.  It it reads 4 ohms, you've found a speaker.  Touch the two ends to a battery, and rub your finger on the battery.  Listen for which speaker the sounds coming out of.  Repeat this 3 times to cover all 4 speakers.

Ensure that you do all that testing in the order I told you; if you find a 12V line and ground, and don't test for voltage first, when you connect it to continuity or with the battery, you'll likely blow something up.

Justin

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

QUESTION: Justin;  I've figured out the power wires and speaker wires but still no audio.  I'm having a problem hooking up the blue wire with the fuse connected to the unit to a wire from the vehicle.  Not sure which it connects to.  What I've noticed is that the unit won't even power up sometimes.  Could there be a ground problem?  I have hooked up the ground wire from the unit to the vehicle.   There is a reset button on the unit.  Does this have to be pushed every time I hook up the wiring?    I have yet to do your speaker test, but will get to it as soon as possible.

Answer
Hi Jim,

The blue wire coming off of the deck won't be used unless you're putting an aftermarket amp in the car.  You can safely ignore it.

If it's not powering up sometimes, you've likely got a loose connection somewhere.  You can ground simply to the ground wire from the factory harness (there should be one), or you can bolt it to the chassis of the car.  Make sure wherever you bolt it is clean from rust and paint, and preferably isn't a bolted on or welded part itself.

Justin