Whine Heard Through My Stereo

L

LukesfirstJeep

TJ Addict
Supporting Member
Joined
Aug 2, 2018
Messages
1,410
Location
Central PA
I've had the same stereo set up for several years with no problems. Kenwood head unit, Sound Ordnance amp, and Kicker speakers. Today, I started hearing a whining noise that gets louder as the engine RPM rise. I'm assuming it's some interference from the alternator. I have two questions.

1. What would cause the noise to start after several years of no noise?

2. What noise suppressors would you recommend?
 
Personally I'd check your battery cables, make sure they are perfect. Then check all the grounds in the engine compartment, especially the block and firewall connections. After that I'd replace the spark plugs because no reason. I wouldn't seriously consider adding a filter or anything, obviously something corroded or broke and is causing your issue. Maybe a ground for your radio or amp?
 
  • Like
  • USA Proud
Reactions: CharlesHS and Jerry Bransford
If the whine changes pitch when the electrical load changes, like if you turn the headlights on, that's likely a bad voltage regulator inside the PCM.

But if the whine stays constant no matter the load, but varies by engine rpm, that's likely a bad rectifier (diode) inside the alternator. There are six of them.
 
pagrey,

I'll check battery connections and grounds. New plugs were installed a few thousand mikes ago.

Jerry,

I'll check if the pitch changes with varying loads, but volume varies with RPM. I checked Rock Auto for alternators, and found it interesting that a remanufactured ACDELCO brand is the most expensive, and a remanufactured BBB brand is more expensive than a new BBB brand, if you include the core charge.
 
  • Like
Reactions: Vasq
Check that your ground for the amp is clean and tight. Bad ground can cause engine noise, and power wires running next to speaker wire. I'd sand the place it's grounded again.
 
  • Like
Reactions: Jerry Bransford
It’s referred to as a ground loop. You can google it. As others have said, it can come from many different places. First thing I would try is tracking down the ground on your amp and head unit and clean up the connection. Mine actually came from the antenna connection on the head unit - the last place I looked.
 
Thanks for all the suggestions, problem solved. I did several things at once, so I'm not sure which particular thing solved the problem, or all things together.

First, I double checked my battery connections, they were clean, but I got another 1/2 turn tightening the connectors.

For the grounds, the head unit was grounded through the OEM harness, and the amp was grounded to a bolt on the transfer case shifter frame. I reran the both grounds to a common point, away from the amp and head unit.
 
  • Like
Reactions: EricT77, MaximusLJR06, pagrey and 1 other person
Top Bottom
Back