Help with Noise through speakers.

[BH1989]

I am in need of some help. I have searched this forum in its entirety and others as well and can not find a solution.

Please read all of my post as there is alot of info here.

Boat info: 2008 Supra 22ssv, 340 Cat Motor, Kenwood headunit, all Kicker speakers, 3 amps, 1 for sub, 1 for tower and 1 for in boat speakers.

Problem: I have a high pitch noise that comes through my stereo in the boat. It is a new problem this year. The noise originates from the electric motor on the throttle body. How can I tell? I did tons of testing and finally removed the throttle body and put it up to my ear when the key is on. The noise happens when the key is first turned on for about 10 seconds. you can here the throttle body motor actuate slightly then it will go away. If I move the throttle lever on the boat, the noise comes back as the throttle body opens and closes. Please note, it does not get louder or quieter as I move the stick. It is a constant high pitch noise. Same goes for volume on the headunit. The noise is constant throughout the volume level.

What have I done: I have cleaned all grounds that I could find, this includes all grounds on the engine as well as on the batteries, amps, bus bars ETC. I have tried all new RCA cables, new power and grounds for the amps and headunit, New head unit, different amps have been tried. I tried ground loop isolators on all RCA outputs on the headunit. I wired everything to its own battery with nothing else connected to it. I bought a new throttle body. I tried different speakers. Changed all settings on amps and headunit. disconnected transom remote for headunit.

If anyone has any suggestions I am open to hearing them. This has been a true roller-coaster and listening to the radio is not enjoyable unless the boat is off or we have the music turned all the way up.

[secondsupra2004]

I am in need of some help. I have searched this forum in its entirety and others as well and can not find a solution.

Please read all of my post as there is alot of info here.

Boat info: 2008 Supra 22ssv, 340 Cat Motor, Kenwood headunit, all Kicker speakers, 3 amps, 1 for sub, 1 for tower and 1 for in boat speakers.

Problem: I have a high pitch noise that comes through my stereo in the boat. It is a new problem this year. The noise originates from the electric motor on the throttle body. How can I tell? I did tons of testing and finally removed the throttle body and put it up to my ear when the key is on. The noise happens when the key is first turned on for about 10 seconds. you can here the throttle body motor actuate slightly then it will go away. If I move the throttle lever on the boat, the noise comes back as the throttle body opens and closes. Please note, it does not get louder or quieter as I move the stick. It is a constant high pitch noise. Same goes for volume on the headunit. The noise is constant throughout the volume level.

What have I done: I have cleaned all grounds that I could find, this includes all grounds on the engine as well as on the batteries, amps, bus bars ETC. I have tried all new RCA cables, new power and grounds for the amps and headunit, New head unit, different amps have been tried. I tried ground loop isolators on all RCA outputs on the headunit. I wired everything to its own battery with nothing else connected to it. I bought a new throttle body. I tried different speakers. Changed all settings on amps and headunit. disconnected transom remote for headunit.

If anyone has any suggestions I am open to hearing them. This has been a true roller-coaster and listening to the radio is not enjoyable unless the boat is off or we have the music turned all the way up.

I'm showing my age, but back in the day you had a noise suppressor at the ignition coil to eliminate feedback. My first try would be an inline noise suppressor in the power wire going to your radio. Check out this link also.
https://www.popularmechanics.com/car...o/a84/1272491/