new head unit not powering on

hi,

I just switched out the factory radio in my 95 cavalier z22. i switched it for a pioneer DEH-P4000UB unit and connected it with a wiring harness that the guy at the instalation shop gave me.

i crimped all the wires and once everything is plugged in and the radio is grounded, the unit simply wont power up. i unplugged it and plugged the old radio and it worked. the new one just doesnt work....

does anyone know whats going on here???

thanks
-chris-

the wiring harnesses are not always correctly pinned. Plug in the harness without the radio and check all the voltages

ok, my buddy suggested connecting the yellow and red wires together (battery and accessories wires). i tried it and now the radio works fine. Only thing is that i can turn the radio on with full functionality even when there is no key in the ignition.

is this a good or bad thing?

-chris-

not good or bad I suppose, but what it's telling me is that the wire the harnesses is tapping for constant 12 volts is good and the one that is tapping switched 12V is wrong