Can I use the old wiring harness from my 1992 Chevrolet Silverado c1500 and wire it with my new radios wiring harness also I connected it with the right wires but it has one more a power antenna/amp t

The blue wire,is the memory wire,all time power to the radio,if it is coming out of the new stereo,and it has to be hooked up to hold the memory and run the stereo.

Where would I attach that wire in my truck

If it say power antenna/amp.it does not have to hook up,but if it is a blue wire coming from the new stereo,it will hook up to a power wire ,that stay,s hot all the time,

I hook up all the right wires but it won't turn on

I'm not sure where the above poster got that the blue wire is power. Blue is a positive rear speaker wire. See http://www.modifiedlife.com/1989-chevrolet-silverado-c1500-car-audio-installation-guide/ Your truck probably doesn't have a power antenna so that would be unused