Stubborn alternator whine
Thread Starter
Intermediate
Joined: Jan 2024
Posts: 37
Likes: 9
From: Cincinnati, Ohio
Stubborn alternator whine
I installed a Boss head unit and a Boss 2 channel amp along with Pioneer 3.5", 5.25" and 6x9" speakers. The 6x9 speakers are run from the amp, the rest are driven by the HU. Since install I have had moderate alternator whine on the amplifier only.
First step was to take the RCA jacks off the amp, whine went away. Actually, with only the right input plugged in there was no whine.
Tried a different RCA cable, still had noise.
Switched from the RCA inputs to the speaker level inputs, noise is still there.
Created a ground bus and tied in the radio ground, the amplifier power ground, the amplifier ground wire on the spkr input plug, the radio chassis, the amplifier chassis, the Crux adapter ground AND the transmission tunnel (metal), still noisy.
Today, I ran a temporary power wire from the battery to the amplifier's power input, still noisy.
Then, I ran a temporary wire from the negative terminal of the battery to the amplifier ground, greatly reduced but did not eliminate the noise.
I'm out of ideas other than to eliminate the amp and put the 6x9s to the HU and forget the 3.5s!
First step was to take the RCA jacks off the amp, whine went away. Actually, with only the right input plugged in there was no whine.
Tried a different RCA cable, still had noise.
Switched from the RCA inputs to the speaker level inputs, noise is still there.
Created a ground bus and tied in the radio ground, the amplifier power ground, the amplifier ground wire on the spkr input plug, the radio chassis, the amplifier chassis, the Crux adapter ground AND the transmission tunnel (metal), still noisy.
Today, I ran a temporary power wire from the battery to the amplifier's power input, still noisy.
Then, I ran a temporary wire from the negative terminal of the battery to the amplifier ground, greatly reduced but did not eliminate the noise.
I'm out of ideas other than to eliminate the amp and put the 6x9s to the HU and forget the 3.5s!
Thread Starter
Intermediate
Joined: Jan 2024
Posts: 37
Likes: 9
From: Cincinnati, Ohio
That was why I eliminated the RCA lines. With the speaker level inputs I should avoid any ground loops.
The curious part was tying the ground bus to the negative terminal of the battery and reducing but not eliminating the noise.
Just a thought, are the radio and amp power feeds from the same fuse or individually fused?
The curious part was tying the ground bus to the negative terminal of the battery and reducing but not eliminating the noise.
Just a thought, are the radio and amp power feeds from the same fuse or individually fused?
