Hi there.

Over the past couple of weeks, it seems my car has developed an alternator whine--a high pitched sound where your acceleration is picked up through the car's speakers. This was a notorious issue for Honda's from the 80s and 90s that had aftermarket stereos, but I could not find any G35's with this issue by searching this site.

I have had the JL Audio 500/1 amp since 3/06, and Braille B2015 All-Season Lightweight Racing Battery since 4/07. But again, the alternator whine is a very recent development as initially indicated.

Any suggestions on where to start looking for a solution here would be much appreciated!

Thanks!

 

I have a completely aftermarket audio setup, and I experience a small amount of alternator whine. Generally the issue is related to ground loops, which are often caused by poor grounding of any device in your signal chain. One easy fix is to reset your gains on your amps so they are as low as possible, this will reduce the whine. I have excellent grounding points, and have upgraded the three major under hood wires, and I still experience it which leads me to believe it is just inherently bad in our cars.

 

if you didn't have noise before and nothing else was changed then it could simply be corrosion. remove all your grounding points and wirebrush/sand/grind back down to bare metal and reinstall the grounds. After you reinstall the grounds spray them with a water displacer like corrosion block, that will prevent this from happening again.

 

+2, I would start with your grounds. Since this has recently come up I would start there.

 

I'd also check the RCAs if the amps have moved at all you could have strained the sheathing or the wiring causing a higher impedance thus less noise shielding - sounds dumb but it's happened on multiple occasions

 

Thanks for everyone's suggestions so far. I have not had a chance yet to check the grounding points or RCA's, but I had a fun, little experience yesterday while I was down in San Diego.

I was in a parking lot on my cell phone with the engine running, and then all of these events occurred:

• The display lights on the dash that illuminate the compass, outside temperature, A/C, etc. dimmed and the graphics became distorted
• The radio shut off
• Several lights came on the dash including Check Engine, VDC, and ABS
• My headlights dimmed and began to flicker

After I turned off my headlights, the warning lights on the dash disappeared and the radio came back on (with the alternator whine still there). Fortunately, I was able to make it back home with no further adventure.

So... I'm guessing there may be a more serious electrical issue at hand here. Does this sound more like a battery or alternator issue?

Thanks again!

 

I'd say check the battery's connections. power could be coming loose or the ground could be coming off the chassis

 

check your voltage with the car running, it should be around 14v. if it's only 12v or less your alternator is going. it probably is not a battery issue, once the car is running the alternator is actually the one providing power and your battery is recharging.

 

alt is my guess
but like said, def check battery connections, or any connections you can find for that matter