Grounding and noise

Hello,

Car: Lexus LX470, 1999

On the wiring diagram, there is one connection that I can't figure out, it's called AGND. Wire is BROWN / White and a small arrow pointing at the connection, saying 2000.

(Regular GND exist too, and, according to diagram, it's grownded under front passenger's seat)

Any ideas what this is, would be appreciated,

Thank you in advance

Thank you!

Now, the next question then, which one do we use for aftermarket head unit? My assumption is it's GND that we need. And if so, what do we do with AGND? Just leaving it not connected?

Thanks!

Gentlemen,

As someone kindly explained to me that AGND on the wiring diagram most likely means 'Analog Ground' my question then would be. What is 'Analog Ground'?

Provided that on the OEM head unit there's also a regular Ground, which is ends up by being connected to the chassis, I am concerned about which one do I use with the aftermarket head unit, with just one ground connector?

Hope someone can shed a light on this!

Many thanks in advance

Thank you Haemphyst!

No, there is no DGND connection. It's Lexus LX470 and AGND is a connection between HU and factory amplifier.

Thanks!

Thank you sir, I'll give it a try.

Gentlemen,

Looks like I am having another grounding problem.

Here's the system set up:

Lexus LX470. Head Unit - Sony WX-S2200

I have replaced the head unit, but kept factory amplifier and speakers. (for now at least)

Amplifier is located under passenger seat, and grounded to a chassis too.

Ground wire goes from the amplifier to the head unit harness.

So here's my problems with and without engine running.

1. Ground wire from amp harness connected to ground of a HU - loud popping sound when switching between tracks of a CD, regardless of engine running or not. No other, engine, noises are present then.

2. Head unit ground wire connected to a chassis - less popping sound when switching tracks, but noise when engine is running.. Noise is independent of RPMs, stays constant, not varies in volume and reminds me of ignition rather than alternator. Not very loud too, only audible when volume is almost all the way down.

3. HU body connected to a chassis through mounts, HU Ground hooked up to a chassis. NO popping sound when switching tracks. Engine noise the same as at #2.

When HU grounded to a chassis, resistance between negative terminal of a battery and HU ground wire is about 0.9 Ohms.

I even tried running a wire directly from battery negative to the HU ground, without any luck.

Honestly, I am out of ideas at this point. Have tried pretty much everything, DC noise filter, grounding either HU or Amp harness to a chassis, (or both) - no luck.

Any help or advise will be very much appreciated,

Thank you

What gauge wire are you using from the HU to the chassis ? Also, have you tried changing HU's ? There maybe something wrong with the HU's ground or power filter's. Just some suggestions for you.