94 Camry car stereo install with factory amp built in.?

I bought the harness online and replacing the factory stereo on my 94 Camry with cassette, radio and CD. When I connect to the connector it doesn't work! Then I check the power of the connector from the car where the color code match with the color of the power wire( yellow on the harness) and there is No power. When I plug back the factory stereo, it works normally. I test the stereo to the ca battery, it doesn' t work. The stereo cd player was working good on my old car. I checked the fuse on the cd player, it is ok. Anyone please help me. Thanks.