electrical weirdness

i've tried posting this on another forum, but no one was interested. I'm really hoping for some help:

I just installed a pioneer dh-p4700 head unit into my 2000 xj. used the wiring harness from crutchfield. pretty straight forward, all connections tinned, soldered and insulated. here's the weirdness:

with NO keys in the ignition, if i turn on my lights...the stereo cuts ON. why is this? and, with the car on, daytime lights cut on and can be dimmed with the dimmer knob! and...with the lights on and the car running, the dimmer knob doesn't dim anything, much less the dash.

i wired color to color and, more importantly, i wired per the instructions. why do I have all of this weirdness??

i can't think of any reason why when i turn on my lights, the stereo should cut on...

any ideas appreciated!

thanks

Obviously something is wired wrong! I'm looking at a wire diagram and there is two wires from the headlight switch for the radio illumination. One is BK/YL and the other is Orange. The orange wire is the main (+) interior illumination wire, it runs to all the gauges and switches. The main power to the radio is pink. Also, Look to make sure that the radio is grounded. Hope this helps.

color to color doesnt mean its correct, for some reason unbeknownst to me, some manufacturers choose to defy the industry accepted color code,

match description for description.

and make sure unit is grounded x2

Yes, check for good (or bad) grounds.

I know the ground on my stereo wasnts protected at all. So when the wire touched the metal mount around the stereo the lights appeared on all by themselves. And wouldnt go off.

That one was fun to find.