Thread: Humming through stock stereo

i think you still have a ground issue. go over them again.

Maybe your radio doesn't know the words.

Its worse in gear than neutral because in gear there is a load on the belt system more than when the car is in neutral. I'll bet the noise is feedback noise coming from the alternator.

Do you have an after market amp or anything? When was the last time the alternator was replaced?

Im sure its a ground somewhere causing it. I had this problem once in an old 95 GTP that I had a pretty good sized audio system in running 180 amp alternator and 3 batteriers. (2 in the spare tire well and a 5500rm MA Audio amp.) If I reved the car the noise would get louder with RPM of the engine.

It may sound insane but Im pretty sure I know exactly what that sound is like. Its either a bad ground somewhere or alternator connection or harness connections on the back of the head unit in the dash.

Need to know what was done and when you first noticed this issues. What was changed whats different?

New battery? New Alt? New amp? If you have an Amp Junk RCA's that dont have very good shielding on them can cause this too. Anything?

something is causing the feedback obviously.

Like others have alluded to you have an issue with the ground. What ground issue did you have and what did you do to remedy it? It sounds as though you have a ground loop which is usually caused by separate grounds at different potentials usually the factory ground at the radio and the antenna ground can cause that. If you have aftermarket componets like Tyler said look into those, if the system is totally stock then look into the Antenna ground and the radio ground. Measure the resistance between them.


Jeff

99% of the time its a ground. those plugs did nothing in the old days, wont do jack today.

body grounds are where id start looking.

Usually plugs will give you a crackling popping sound. Ground loops and issues will give you alternator whine.

Jeff

You need to pull the radio out to check. The chassis ground could cause an issue, but you seemed to have that fixed. Now look at the radio.

Does this sound increase and decrease with engine RPM?

Does it get sound like a whine or is it a hiss?

When did it start, or has it been that way since you got it? Has it progressively gotten worse?

When you say that you pulled the fuse I have to assume it happens even with the radio off.

Is your stereo totally stock? If not what has been done?

Please be specific in your answers.

Jeff

I would confirm that. It will tell me if it is alternator whine a failure in the radio itself or a combination.

Based on your answers since it does this with the radio off, I believe this to be the amp is on for the chimes since they sound through the speakers. It is either there is a ground loop between the antenna and the ground. Test by ohming between the two. It should measure 0 to several tenths of an ohm. Try disconnecting the antenna and playing a CD or see how it responds when off.

The other 2 possiblites are defect in the amp (likely caps in the input section of the power supply) or other defect. The other option is the radio itself.

i don't know exactly how the info is passed back and forth with the interface to the car, but those are the likely things to look at.

Jeff