My problem has been going on for quite some time and I've been beating my head against the wall trying to figure it all out. My equipment is as follows:
The story first starts out when I only had the components, 6x9's and the 4 channel amp. Everything worked just fine without any issues... Untill the day I decided I wanted my subwoofer back. I ordered up the 2nd amplifier and installed it as soon as I received it. Now, the 4 channel amp has an 8 awg wire running down the driver side door sill all the way back. The ground is going to the seat bolt on the respective side for the amp. The new amplifier I decided to get some 4 awg wire and run it down the passenger side as there wasn't enough room on the driver's. I grounded the mono amp to it's respective passenger side seat bolt. Right about now is when the ish hit the fan. I started the car up after completing the installation only to find the alternator whine of doom screaming out of all 4 speakers. I proceeded to remove the new amp to see if it was just the new amp that was throwing things out of whack. Even with the new amp removed and all new wiring unhooked, there was no change. The nosie was present with everything hooked up the way it used to be. All of my pre-out cables are crossing any power wires at a perfect 90 if at all. I proceeded to hook a single speaker directly to my head unit via the existing speaker wire and the noise was close to gone, but still there. In essense, it was much quieter only coming from the head unit in comparison to being amplified via the PG Amp. I proceeded to hook the entire system, power and ground to my father's battery to see if it was something within my internal charging system (alternator/battery) and the noise went away.
Now, my situation is this. Many people have told me that I should get a ground loop isolator or replace the ground wiring on my alternator/battery/chassis. I am hoping that this will simply be a last resort and that there is a root cause somewhere deeper. My reason for saying so, is that the system worked fine with the single amplifier, and then did not work anymore after the installation of the 2nd amplifier even when it was unhooked. My mind leads me to believe that something must have blown, not just gone bad over time. I went to Murray's to have my charging system tested and it was charging around 13.7 volts. He said it also stated that I had a normal charging pulse. I was thinking that it would have been possible to blow one of the diodes in the alternator to create this awful noise, but if the pulse is fine, then that's not the case. I'm very close to just ripping my alternator out to have a look.
Does anyone have any certainty into a given fix for this problem? Or am I going to end up tearing my car apart trying to fix this bastard of a noise! Any help is much appriciated.
#12494, "RE: Alternator Whine help. Heavily researched." In response to Reply # 0
i dunno on here... i know a little about stereos and systems and whatnot...but you gotta be picking up the noise in the signal wire and that amplifier wiring...sounds like youre creating some sort of magnetic fields or something in the car. dont quote me on it or not (pick up a copy of the Car stereo cookbook by Mark Rumreich ISBN: 0070580839, or the newer edition) but that explains a lot about noise in stereos. anyway i think you should try and simplify your stereo wiring, it sounds like youve over complicated your power/ground distribution.. in my particular case im running a SONY XM-2200GTX hooked to a pair of type R DVC 12" alpines., with another 500 watt sony xplod amp for the components.. but i have it all run off of 2awg wire off the battery to a distribution block in the trim panel by the driver rear speaker..from there it splits into 4awg wire and a 8awg wire for the two amps...which reside in the trunk, with the grounds attached in the trunk also. I then run the signal wires down the passenger side to the rear. that way i kept all the wires as far apart from each other and the amps and grounds as far away from the alternator as possible. but if i were you, id see if i can simplify the wiring as much as possible and see if that helps...it may not but at least if you do theres less wires to have to chase around... ill do some reading and see what i can find out about eliminating alternator noise.. but i highly doubt its anything wrong with your alternator, i think it has more to do with where your stereo wires are ran. they may be close to a factory ground or something.
#12501, "RE: Alternator Whine help. Heavily researched." In response to Reply # 2 Sep-14-06 02:43 PM by OUDLES
Thanks for the insight guys. I was actually planning on getting a distribution block and just running both of the amps off of the single 4 awg wire coming in, which would then be split to each of the respective 8 awg wires for the amps.
Now my only problem with a bad ground is that it all worked just fine and dandy before the installation of the 2nd amp. That is where I'm having trouble believing that a ground is bad. It basically was working awesome, installed the amp, and then there's this noise from hell. Just to be sure it wasn't the new wiring, I unhooked the new amp completely and the noise was still there... I'm stumped. I'll be having a look at it this weekend and I'll see if I can snap some pictures to show you what the hell I'm working with.
ill do some reading and see what i can find out about eliminating alternator noise.. but i highly doubt its anything wrong with your alternator, i think it has more to do with where your stereo wires are ran. they may be close to a factory ground or something. 