ok so Pioneer wants me to run a power line directly from the batter to the H/U....
 

Can I just wire up the 2 wiring harness'?

Do I HAVE to run a direct line from the battery?

What do you think?
Past experiences?

All help is very much welcome!:rockon:

you dont have to, but you really should, the new deck will sound better if its getting the power it wants

run the line through the firewall wherever is easiest and run an inline fuse that is suited to the deck and you are set

i have had my alpine hu setup both ways in my ek civic, no amps, mediocre aftermarket speakers, not sure i noticed a difference, but i had minor power issues before and they havent been back since i ran a better power line

No need to do that, use the harness, you want it to turn off with the key.

if you run it correctly it will turn off with the key, it still receives acc from the harness :)

what head unit do you have

It won't run with the key off if you run power to the battery, and not the harness. The headunit is turned on with the ignition wire.

To the OP:
You don't need to. I've ran Pioneers, Alpines, and now I have an Eclipse 7200 (BEST headunit I've ever had). I hard wired mine also, no harness. I didn't use the aftermarket harness adapter because I didn't need it. All I needed was power, ground, and ignition lead. Didn't need the speaker were from the stock harness because I have amps running my three sets of components (ran active also). I have about 200 feet of 14g speaker wire in my car also. :eek:

Oh, and Pioneers are notorious for having bad grounds, so you will probably be better off running a separate ground wire, and probably won't have to worry about running power to the radio from the battery.

If you're going to be using an amp or amps, ground the RCA preouts also. Here's a picture of an RCA ground loop.
http://i62.photobucket.com/albums/h1...PioneerFix.jpg
It will stop ground whine/squeal through the RCA's.

pslsnakes, thats truely a good picture of groud looping the rca outputs. as for power, using the factory harness is fine, howver, if you plan to upgrade your system, i suggest you run dedicated power from the battery and still use the harness. THat means, connect all wires from aftermarket deck to the factory plug in harness besides GROUND and CONSTANT 12v. that way your deck will run at its best if it has dedicated powers ( will draw as much current as it needs)

for my system, the only wire i used from my factory harness was the ignition. power, ground, speaker, antenna are all on its own since i got amps running fronts/rears and subs.