Aftermarket Stero Install for a 2000 GS

I just recently bought an aftermarket cd player for my 2000 Eclipse GS. When I removed the stock Infinity stereo system, I noticed 2 wiring harnesses opposed to 1 that I usually see in vehicles. Theres one smaller one, with about 4 wires, and a larger one that looks like your typical stock vehicle wiring harness. When I connected all of the wires from my Kenwood cd player to the wires from the main harness, I get no power to the player. It will not turn on at all. Does anyone else know what I need, or what Im doing wrong? Thank you very much in advance.

i think its because of the factory amp.  the shop i went to had to charge extra to bypass the amp

mitah 20 bucks on ebay, it allows use of factory amp with out bypass. Ive bypassed and it sounds way better with mitah unless you upgrade all the speakers.

i just spliced the wires for my 2 jl's and aftermarket cd player without spending a dime. works flawless

I have an Infinity 4 disc CD changer that has stopped working on me. Is that what you took out of your 2000GS and do you think it would work in my 2000GT?

yes