I bought a little beater Saturn ion quad coupe. One issue that seems to be perplexing is the stereo picks up this annoying whine through the speakers as you drive. Definitely like alternator interference. The stereo when I bought the car was an aftermarket stereo but didn't have Bluetooth I swapped it out for a modern aftermarket radio with Bluetooth. Both stereos had the same issue. The radio is so small adding a ground wire to the case would be a challenge. I have read the ground could be the issue? Is there anything else I could check that would cause this? It's an 04 ion quad coupe
Annoying whine through car speakers
- Thread starter wheelman
- Start date
Excessive alternator ripple? Either Autozone or Advance Auto has the capability of testing the alternator while it's in the car, and ripple is one of the things their tester checks for.
Unplug the Alternator Regulator or Isolate the Charge Lead from the system, Like Brian said.....A/C Ripple can cause interference. And not just in the audio system! Learned this the hard way many years ago with Dodge Cummins powered trucks with the in & out of torque converter lock-up symptoms.....A/C Ripple would affect the TPS voltage.
Crappy radios without good PSRR. Yes you need a filter in series, but I don't understand "so small adding a ground wire to the case would be a challenge". You need approximately 4 cubic millimeters to solder a wire, *anywhere* that solder sticks to. Ifs it's steel, copper, or brass, and solder doesn't stick, scrub off a little plating/paint/whatever to get to bare metal. I am NOT yet suggesting that bad ground and adding that is the solution.
Also make sure it has the correct, resistive plug wires. I suspect it is not alternator but rather, ignition system noise.
You can determine which, simply disconnted the alternator while the engine is running. You will still have the ignition noise then, just don't run it too long to drain the battery excessively. If the noise isn't there with the alternator disconnected, replace the alternator or get a filter, depends on your confidence in the quality of the radio which to replace next if not the radio itself.
Also make sure it has the correct, resistive plug wires. I suspect it is not alternator but rather, ignition system noise.
You can determine which, simply disconnted the alternator while the engine is running. You will still have the ignition noise then, just don't run it too long to drain the battery excessively. If the noise isn't there with the alternator disconnected, replace the alternator or get a filter, depends on your confidence in the quality of the radio which to replace next if not the radio itself.
Last edited:
Saturn Ion's don't have ignition cables.
On our old Mercury from the 90's I can still hear the whine through the speakers! It was factory tape/speakers but the body grounds / chassis grounds - shot and the speakers whined with the RPMS of the engine. 
Lived with it for many years until the head gasket blew on the 3.8L.
Lived with it for many years until the head gasket blew on the 3.8L.
A few quick suggestions/thoughts...
If you have an external amp, run a ground wire from the amp grounding location to your radio grounding location.
If you have an external amp, use a ground loop isolator.
If no external amp, run a better ground and ground the chassis of the radio to the frame...if it is a "value" radio, run a ground right to the battery.
Install a capacitor on the power lead
Buy a better head unit...
If you have an external amp, run a ground wire from the amp grounding location to your radio grounding location.
If you have an external amp, use a ground loop isolator.
If no external amp, run a better ground and ground the chassis of the radio to the frame...if it is a "value" radio, run a ground right to the battery.
Install a capacitor on the power lead
Buy a better head unit...
- Joined
- Jul 11, 2014
- Messages
- 4,118
A bad diode in the alternator can cause this. As others mentioned it's excessive ripple. Can also be the fuel pump.. with the car running unplug the alternator and see if the noise stops.
A poor ground on stereo can cause this. You can ground it to battery temporarily and see if goes away to isolate if car radio or something else.
Too many variables here to go wrong.
Bas ground at alternator.
Bad ground on chassis and engine connection.
Stereo? Pioneer, Kenwood, Alpine or Amazon sourced Chinese stuff?
Bad ground at stereo connection.
Etc.
Bas ground at alternator.
Bad ground on chassis and engine connection.
Stereo? Pioneer, Kenwood, Alpine or Amazon sourced Chinese stuff?
Bad ground at stereo connection.
Etc.
