I have the cda-9815 alpine head unit and installed it myself with the help of a friend. I have been using it for several months now. I just found out that the internal amp requires a direct connection to the battery. (when i installed it, i just got the appropriate wiring harness for my car and crimped the harness to the wires from the 9815 and plugged it in).
1) have I been unknowingly damaging either my speakers (alpine spr-136A components in front, spr-174A coaxials in back) or my head unit by playing it without having the proper battery connection?
2) I intend to immediately fix the discrepancy, and I would like to know what kind of amp wiring kit you guys would reccomend, or if i should just buy the 10 gauge wire and connectors and fuse myself.
3) is there a way to leave the 9815 in place to make this one change or will i have to take out the whole thing and then reinstall it?
1: probably no damage.. it depends on how loud you play it and how much current it draws.. the larger cable prevents you from melting the wires of the factory harnesses due to the larger ~15A current draw of the unit.
2: go to radio shack and get a spool of 10AWG power wire, and an in-line fuse holder with a 15A fuse. that's all you need, along with a ring terminal for the battery post bolt, and a butt-end connector to connect to the head unit.
3: nope, gotta pull the head unit out again. I've had mine in and out countless times making little changes here and there.. you get used to it. I can actually get into the car and pull the entire dash with my eyes closed now. I did it once.. just to see. haha
Just a little update. I did like you said and got the supplies from radio shack, got the HU hooked directly to the battery and grounded with 10 gauge wire. It hadnt burnt any of the wire and id been playing it for a while, but i feel better now knowing its hooked up correctly. Thanks for the help Glasswolf. For my next little project I'm going to install some dynamat xtreme I got off ebay.