Cybernetic

Hello CL. I asked this question in the ES300 forums wihout realizing that there was a section specifically for audio.

I recently bought a JVC X50BT for my Lexus ES300 as well as a Metra wiring harness (amp integration included). The installation went smoothly until a couple day ago when I started noticing a slight buzz in my speaker on 0 volume. I looked into it and tried as best as I could to try and fix it as well as re-installing the system to make sure I didn't screw up the wires.

I looked online and people suggested a ground issue. I took the HU out and hooked some speaker wire (~20 guage I think) to some metal (vertical bar about 2 inches wide and half inch thick) beside and behind the HU to various parts of the stereo (ground wire from the included wires that hook into the harness, one of the screws on the side, and just touching it to the HU itself) but to no avail.

The recommended solution right now seems to be a ground loop isolator. I've heard this is just a "band-aid" for the real problem. I'd rather deal with this thing than cover it up.

Any suggestions?

I don't know if this is relavent:
~The ground wire coming from the HU is thicker than the harness wire
~The installation kit is made of plastic
~Only one of the antenna wire's originally in the OEM car stereo is hooked into the aftermarket HU
~The butt connectors are secure on the stereo wire and harness wires
~The buzzing is gone when HU is on with battery, hums when I turn the key a little more, and buzzes when the car is on

BTW: I'm trying to upgrade the system peice by peice, so I would really love for this problem to be resolved. Next on the list are speakers

rogzballz

iTrader: (9)

Yeah this is usually a grounding issue, check your butt connection on the ground wire, then you can try grounding the HU with a separate wire connecting the back of its chassis to a real metal ground of the car. Even if you have metal pieces in the dash, it may not be really grounded. You want to find a spot on the actual car's body and sand down the paint and use a self tapping screw. You can then cover it up with some touch up paint to prevent rust.

Cybernetic

I went out and bought some 12 gauge wire and some ring terminals. I hooked up one end to the chassis and the other to the ground wire. No change. I tried it with the stereo chassis. Nothing again. I tried making sure the amp was grounded and there was still no change.

It's not a loud buzzing, but a faint buzz. It's driving me crazy because I know it's there.

Could it be something with the speakers? When I unplug the RCA and the stereo is on, the sound disappears but since no speakers are plugged in there is no music either.

EDIT: Could it be the lack of ground for the RCA? The harness converts the audio coming in to RCA outputs. So there is no ground wire... unless there is? Could it be this?

EDIT: I tried it with some 22 gauge wire... nothing... again. Out of ideas to troubleshoot with.

Cybernetic

BUMP.

So I went to Radioshack today and bought the ground loop isolator. I hooked it up and sure enough 90% of the buzzing disappeared. I found a great isolator online that's 4-channel and relatively cheap, so I'll end up buying that one. Luckily, the Radioshack guy let me return the isolator I bought to check it.

I've got a couple quick questions:
1. Where is the 1997 ES300's amp grounded?
2. Does it matter that I use a smaller gauge (thicker) wire for ground than the stereo wire?
3. Is there a way to figure out where there is a ground loop on an aftermarket HU and factory amp?

Cybernetic

BUMP.

I've given up on trying to solve this thing. The best info on the matter I've gotten is that the ES300s are notorious for aftermarket head unit and factory amplifier conflict. For all those experiencing this problem: buy a ground loop isolator.

The following is a link to a decent, cheap, and 4-channel isolator: