Car Stereos: aftermarket install, no sound

Question
Installing an alpineVRCD500-SDU into 98 Jeep grand Cherokee limited with factory infinity gold sound system. Used factory harness adaptor, triple checked my wiring, everything looks good. Deck poers on, display comes on but no sound. Hooked factory radio back up and speakers all work. Tried the Alpine again after wiring power antena and remote amp up to factory amp wire, and still nothing, same result as the first time. What do I do?

Answer
Hi Reggie,

I'm confused about the product that you're installing.  The model number VRCD500-SDU is not an Alpine head unit; it's from Virtual Reality Sound Labs (VR3), and I can't find much information about it as the manufacturer does not maintain a web site with product support.  The VR3 unit's faceplate may look similar to an Alpine head unit in the button color and layout, but in terms of product quality, they're at opposite ends of the spectrum.  

An Alpine head unit would have a blue/white wire for the amplifier remote turn-on output, with a solid blue wire for power antenna.  In your vehicle, you'd need to connect the blue/white wire to the solid blue wire in the adapter harness to properly activate the Infinity amplifier.  However, if you have a VR3 unit, as far as I can tell they do not follow the CEA wire color code, and the blue and blue/white wires in their harness may be speaker outputs.  

Do you have an owner's manual for your new head unit?  What color is the wire you're connecting to the factory amp activation wire in the adapter harness?  

Brian