03 dodge

Make sure none of the speaker wires are touching any bare metal anywhere...a shorted speaker wire can cause the internal amplifier to go into protection mode.  Unfortuntaly protection mode is the same as normal operation, the onoly difference being there is no sound output.  There's no visual indicator on the deck or anything though, so you have to test all the wires.

Simple way is to pull the deck out and just connect the essential hookups--power, switched, and ground.  Then with all the speaker wires taped off to avoid contact with each other, hook up one pair of speaker wires at a time.  You should get sound with at least one of the pairs.

Also I just assumed this was the case but maybe I should have suggested it first...make sure the head unit's blue remote turn on output is connected to the wiring harness's blue wire.  Should be labeled power antenna.

Okie let's clarify a few things.  First off, not all head units have a separate power antenna and remote amp turn-on wire.  Many just use one.  This alpine, however, DOES have a separate one and you are correct about the coloring.  It follows the EIA standard.

I was assuming that #1: he was using a wiring harness like the Metra 70-6502, which only has a single solid blue wire on it.  And #2 that the alpine had just a single remote turn-on output.  Obviously I assumed incorrectly on #2, and worded #1 wrong.  lol sorry for the confusion, and thank you ezridr for the correction.

The main point I was trying to make was that even though the wire is labeled as "power antenna" on the metra harness, if the vehicle has an infinity factory amplified system, the factory wire corresponding to the solid blue "power antenna wire" on the metra harness is actually the turn-on for the factory amp.

Therefore, my wording on the last sentence should have been "make sure the solid blue wire in the metra harness is hooked up to the amp remote/system control wire of the alpine's harness."

Since you specifically said that "It doesnt have bose or infinity" I decided not to first suggest the bit about the remote turn-on wire because it would not help you assuming you do not have an infinity system.  It was just kind of another thing to try if all else fails.