I'm trying to install my D3 into my '99 Lexus ES300, using the factor speakers, amp, sub

I stopped by a local car audio shop and bought a wire harness there. It has power connections for the head unit and RCA connectors to hook up the preamp outputs. I talked to installers at different audio stores and they said that harness will allow me to hook it up to the factory system. The cable looks really similar to this: http://cgi.ebay.com/92-99-LEXUS-ES300-T ... 46QQssPage NameZWDVWQQrdZ1QQcmdZViewItem

However, I hear a high pitched sound coming from the speakers and it makes a "popping" sound as soon as I cut power to the D3. Any ideas how to remedy this problem?

The whining, does it go up when you rev the engine? IF so then you've got alternator whine. you can try moving the avic ground to a metal support in the dash, or pick up a couple of ground loop isolators. The turn on thump, you can try trhowing a 1k resistor on the remote lead. Might work, might not. Hard to say.

I was testing it in accessory mode, so I'm not sure if it is from my alternator. All grounds are connected to a metal support inside my dash.

EDIT:

I drove my car around and I think the sound of the high pitch whine is slightly affected by the alternator. Need to get a ground loop isolator, right?

yes that should help

OK. I will order them tonight. Will they solve the popping noise after I cut power to the D3?

Hey, before installing the Ground Loop Isolators, try this trick. attach a wire using an o-ring to the back of the radio (where the screw hole is for a backstrap). Then, take that wire and attach it to the RCA shield wires (the negative outside of the RCA jacks. If the noise goes away, there's no need for the isolators. If that doesn't work, try grounding the radio with at least a 16AWG wire to the firewall or kickpanel (make sure it's BARE metal) hope this helps. any ?'s hit me up.

Thanks the help. I'll be trying that out this weekend along with this:

http://www.sminntech.com/techai.html

I bought a couple ground loop isolators and they help a little bit, but does not get rid of the hum completely. It didn't solve the thump problem either. Hopefully your trick will work and I'll update with any progress.

Tried Stereotype's trick, didn't fix the high-pitched noise

Tried the 5v voltage regulator on the amp turn on line, didn't fix the subwoofer thump

I did however notice that if I unplug my radio antenna, the high-pitched noise goes away. The high-pitched noise is consistent no matter what mode I'm in.. radio, nav, or iPod. With the antenna unplugged, iPod plays w/o any unwanted noise.

Can anyone explain this and/or have a solution to this very odd problem?