no power to headunit

  hello, i have an 89 chevy s-10, i recently tried to install a new sony stereo in it, all the wires were hooked up correct(the old harness was previously cut by the old owners).  it seems to get power it will take and eject cd's but there is no display on the headunit. any help would be great

There are 2 yellow wires in the radio harness. One is switched 12 volts and the other is a speaker wire. Did you use a volt meter to make sure you connected the correct yellow wire of the truck to the red wire of the radio?

And did you connect both the yellow and red wires on the new cd player? One of the yellow wires mentioned above, the speaker wire on the factory wiring side commonly has a brown wire attached beside it. Top Secret, I can tell you but then my wife will kill me.

You are correct on the wires you mentioned.  Yellow is switched power, it is to be connected to the red wire of the new radio.  Black is ground, it will connect to the black wire of the new radio.  I do not remember an ORANGE / black wire.  However if there is an orange wire going to the cigarette lighter, that should be your constant 12 volts, connect the yellow wire of the radio to that wire.  If there is no cigarette lighter, you will have to use a volt meter and test the orange wire you are talking about.  Chances are it is a constant 12 volt wire, but check it with a meter.