I'm almost done connecting the metra harnesses with my Pioneer AVH-4100 HU harness and I have a few questions. Here's the setup:

Pioneer AVH-4100DVD HU
70-7551 wiring harnesses
SWI-PS Steering Wheel controls
Video lockout bypass

I tapped into the new HU's harness ground wire for the video lockout bypass so I'm good there. I also have to ground the SWI-PS steering wheel controls, two black wires on the metra harness (one for "amp ground", the other says just "ground"), and another ground wire coming from the car's OEM steering wheel controls.

I don't want the ground loop or alternator whine scenarios. I've searched and the common thought is one grounding location is the best way to stay away from problems. Here are my questions:

1) What's the best way to ground the remaining four wires?
2) Do I have to ground both metra harness wires even if I'm using my stock Bose amp and speakers?
3) Should I ground the remaining wires separately or should I connect them together and run a ground wire to the car chassis in the same location as the HU ground wire? Should I just tap into the new HU ground wire?
4) If I ground them separately, should I ground them to the same location as the HU ground wire?

 

You should always strive to use a single point ground.

Why?

Contrary to popular belief, chassis ground on the car is not all the same potential.

For example, you can have high return currents flowing through the chassis back from your amplifiers (say 20A), so if you tapped two separate grounds, there can be a voltage potential between them. Say there is even a 0.01 ohm difference between two grounding points. If 20A is passing through the chassis at that point you can have a 200mV difference.

 

Gibby: Please let me know how everything turns out with your setup! I have a very similar setup and will be getting it installed very soon.

Here's mine:
1) Pioneer AVH-P4100DVD
2) PAC harness
3) Pioneer CD-BTB200 (Bluetooth adapter)
4) JDM DD dash kit

Thanks

 

Everything turned out great with my install. (This was my first radio install and if you have any knowledge about tools, you should be able to save some money by doing the install yourself, just take your time) The only thing is my radio reception is awful even with the diversity antenna adapter. Everything on the Metra/Pioneer harnesses is connected right so we'll see. Any suggestions? I have a window integrated antenna that got crappy reception to begin with. I'll troubleshoot that later.

I bought a pre-wired bypass on ebay for $10 so you can watch DVD's while driving without having to insert a switch anywhere. The Pac SWI-PS install was kind of a PITA. Like others have said, I suggest soldering wires on either side of both resistors so it makes it easier to connect into your stock harness and the white Pac harness wire. Programming wasn't as bad as I thought it would be. Just be sure you keep the dash apart when checking if it works and follow the directions carefully!

I installed the headunit and kept the factory bose system. I'll upgrade later but even with the new HU in itself, the sound is much much crisper. I installed the Pioneer AVH-4100DVD and I love it! Ipod integration was one of my main reasons for buying this HU and I'm not disappointed to say the least. Now I'm going to hit the road and enjoy my new HU.

 

Congrats!

How's the sound quality? I've heard many people end up getting distortion from the Bose speakers when they run an aftermarket head unit. Are you having any of these problems? How's the bass?

Thanks.