1999 Lexus Es300 Factory Amplifier Help
Hello everyone,
This is going to be a little bit of an open post, as I’ve been struggling with this for the past month ago, so some of this will be frustration/venting.
I decided that I would put a BOSS BE10ACP headunit into my factory sound system in my 1999 Lexus es300. Everything wired up ok and works, and I followed the instructions correctly with the METRA 70-8112 integration harness to keep my original amplifier wired in. I turn on the headunit for testing, and I’m getting this horrible whining/ feedback noise with ignition on and no engine running. Definitely coming from the speakers.
I Used Google AI and it’s identifying it as a ground loop problem. Plugged in a set of Amazon ground loop isolators, and that reduced the whining by 95%. Unfortunately, this compromised the deep bass that the factory speakers come with. I asked for other solutions, and it recommended a scosche SLC-4 set in the LOC configuration to reduce the voltage coming out of the headunit. No dice, same problem. Grounded the outside shielding of the RCA Cables on the METRA 70-8112 harness to the chassis ground I created for the radio ground and there was no change.
I’m at the end of my rope and sanity here, and now Google AI is telling me I should run a dedicated power wire from the 12v battery in the hopes that it will “clean up “ the power feed going into my new head unit.
Before I go through with this and delve deeper into the rabbit hole, has anyone had a similar problem (preferably same brand/vehicle/year) that they’ve resolved without the use of a ground loop isolator? If a ground loop isolator is the only option that I have to keep my factory amplifier, is there a specific brand that the AV community likes to use to not compromise the 20-50hz signal range? Can I bypass the factory amplifier and keep the subwoofer without needing to add more hardware?
Essentially I want to do this the most cost-effective and minimal effort, but there is usually a trade off between the two.
Would love to hear anyone’s thoughts on this, it’s only my 3rd system I’ve wired together, I’ve never had this problem before, and it’s driving me nuts that I can’t figure it out! Please let me know, and if you have a consultation fee, I’ll pay it because at this point it’s probably cheaper than continuing to go down the rabbit hole without some Subject Matter Experience.
TLDR; Car Audio AV noob seeking assistance from experienced AV techs to explain/ assist me in getting my sound system right. Thank you in advance!