1992 GMC Sierra, CD wiring

I have a 1992 GMC Sierra Pick Up Truck, full size.  I am putting in a CD player made by sony.  My truck only had a radio before, no tape or cd player.  There are only 6 wires to the back of the radio: Black, White, Gray, Red, Orange, and Yellow.  I cant seem to get anything to work.  The CD player will sometimes come on, but no sound, and it says failure for the radio, which i am thinking i dont have the antannea wired up right.  The speakers do not put out any sound either.  And the Head unit only works sometimes, not all the times.  Please Help Me!!! 

Thanks Mike

U had to get that special kit for the dash right? If so the radio wiring wasnt actually goin to the radio. The tuner is to the lower left of the where the radio was and u have to wire the radio to there.

The original radio is still in the truck,  i cut the wires that were leading to it.  To wire up the head unit i bought.  I did buy that kit that you have to take out the center of the dash where the hole is for like loose change and stuff, my original radio sat above the a/c and heater controls in the gauge cluster dash thing.  I just need to know what colors lead to what in a 6 wire radio like i have, and what i should wire them to in the head unit.

Thanks Mike

like autoobession said the wires you need are at the tuner pack which is right above your gas pedal. just get  a 70-1858 metra harness and it will plug right into the factory harness and you just need to hook up your aftermarket harness to 1858 and your done. also your ant is also plugged in on that tuner pack. you will also need an ant. adapter.

Like they said-wire the stock connector back in, since you've hacked it, and get the metra plug. All you will have to do then is wire the metra plug to your radio and plug the metra harness into your stock connector.

Hotrod-

Do you have the Metra harness for your particular year/model of Chevy? If not, go and get it. Using the stock plug that came out fo the back of your truck's original radio, all you will have to do is wire your new head unit to this plug, and plug it into the stock wiring-no messing with the tuner module or anything else.

Metra plugs are usually available for sale at Circuit City, GoodGuys, Walmart, or any other place the deals in or installs aftermarket sound stuff.