head unit parking brake wire

Hey guys I have ran into some trouble with installing a CD/DVD Player; its a Legacy LD33MU.  I soldered all the harness connections and they are all correct except for the parking brake wire; this one i dont have connected at all.

Heres the problem:

There is power going to the cd player, its just it wont turn on.  I hold the reset button down and then quickly put the face plate on and sometimes the LCD screen will flash quick(literally a fraction of a second) and then turn off. Also when I put the front display back on after hitting reset, the front panel's red LED color turns on for a few second then turns off.

My Question:

Do I have to have the parking brake wire hooked up to something for the cd player to turn on? is that why it wont work?

Any other ideas are welcomed...  Thanks for your time!

have you check the voltage on both the yellow constan and the red  wire should read 12 volts when swicth turn on  last but not least what kind of car is some cars don't have the 12 volts when you turn the swicth on  the parking wire is only for watching tv while in park  but this wire is not going to prevent the radio from turning on  good luck

I read it. It said that if the brake isnt on, the screen should display a message about car in motion...so with the manual saying that, the head unit should turn on in the first place without it being hooked to the parking brake(all the parking brake does when its engaged is present a 'ground' to the wire)

Its a 2005 Jeep Grand Cherokee Laredo. Ill check the voltages on the harness again but i can assure that its wired correctly...but ill check it again

Ill get to that later this afternoon, im stuck at work right now:-( lol.