Audio Systems: installing amp, rca inputs, volvo 850

Question
hello, i have 95' volvo 850. I just installed an after market head unit and Im trying to install the amp. there are 2 rca style female pluggs from the head unit one is aux (grey) and the other is not labled (black). I have the blue remote wire a solid ground and the power hooked up and the speaker wired too but the only noise i hear is a thump and slight feedback every 5-8 seconds is there a certian way to wire the amp that you would recomend.

Answer
aux is usually an auxilary input for hooking up an MP3 player or something.  The black ones are probably the output so use them.  They should go into the rca inputs on the amplifier.  Does the amp have a light on it that lights up and stays lit?  Does it have a protect light or a warning light or anything that lights up?
ARe you using the amplifier for the door speakers or for a subwoofer?
What happens if you unplug the RCAs so that the amp only has the remote, power, ground, speaker and nothing else?

Let me know.