2003 chevy silverado new radio

i have just uninstalled factory radio and i am trying to install a new stereo but my problem is that the accesory wire does not give enough power to turn the unit on is there something else that i need also before the factory radio would turn off when we would open the doors any help will do thank you

first off, there is NO accessory wire in that vehicle, so if you think you are on an accesssory it is probably the data buss, hope you didnt fry the BCM!!!!! You will need an interface to get an ignition and keep the RAP (retained accessory power), this is what keeps the radio on until the doors open. We always use the GMCHIME from Soundgate, Metra and a slew of other companies make them also. Jazzy

thank you very much