Alt. Whine

[OneQuikV6]

Hi Guys,
Just got done wiring the new system and while it's not done yet, the major wiring is done. I'm getting some pretty severe alternator whine and am not sure what to do. Here's the high points:

8g power wire ran on the passenger side directly from battery to trunk.

Signal/speaker wiring ran down driver's side. Using good wire as well. 16g speaker wire as well as good Scocshe RCA stuff.

Grounded in the truck to the trunk hinge bracketry - sanded to bare metal - star grounded.

All grounds are grounded to a common location. Used a Gold Plated distribution block for power and one from ground as well.

Gear:

Sony CDX-7850 head.
2 - RF Punch 100a2
1 - Older Targa 300w 2 channel amp for rear fill.
Audio Control 3XS Electronic x-over
JL dual 10" Power Wedge enclosure running off one of the Punch 100's.
Pioneer 2-way 6x9 for rear fill. (Cheap but new) ran off the Targa.
Infinity Kaapa 3.5's in the front - (Not yet installed or hooked up) - to be ran off the other Punch 100.


Is it possible that the front speaker wiring is causing this to happen due to not being hooked up yet. All factory speaker wiring was replaced with 16g stuff, so, none of the factory speaker wiring is connected. The front wiring is simply cut off and laying in the floorboard until UPS gets here with the Infinitys.

Every piece of this setup has been in my other previous cars with NO noise heard. The only new component as it stands right now is the Pioneers. (in 4x10 adapters, btw)

Any help guys? I think I was very meticulous about stuff, so I'm not sure where I went wrong. Any chance that the fuel pump hot wire kit is causing this?? Casper's kit by the way.

Thanks in advance!

 

[mcss383]

well not sure what it could be...but here's what you need to check. Double check all the wiring just to make sure. I would also try to move your ground points to the frame...

Also, turn the gains on the amp/s all the way down (with your head @ 1/2-3/4 full volume). If you can't hear anything slowly turn up the gains. IF you get engine noise when the gains are all the way down then go to the next step, if not, there is your problem.

Try unplugging the antennea from the head and see if it goes away. sometimes the antenna will cause some ground probs.

If not:


1)
Unplug the RCA's from the amp. Go to radio shack and buy the cheapest/smallest rca's they have (y-adapter maybe). Then cut the plug loose (with several inches of wire left). Strip the wire and tie the two leads together. (or go buy just an rca and solder a wire from the center conductor to the outer sleeve). This is called a muting plug.

Now, plug the muting plug into the rca inputs (you will need 2 or 4 mute's if you have a 2 or 4 channel resp.). Once thats done start the car, turn on lights a/c etc and see if you have noise. If you don't, then you know the amp is good. if you DO get noise, something is wrong with the amp.


2)
If the amp passes that test, now its time to move the headunit to the back of the car with it basically sitting on top of the amp. Use a 1ft rca to connect them. NOW if you get noise, its the headunit thats at fault. If no noise, then its fine.


3)
If all the above passes, then the problem lies in the rca's going from the head to the amps. maybe a cut in the wire that is shorting or something.


If the problem is fixable (ie not from the hotwire kit, ignition rfi, etc) that should pinpoint the problem and solve it.


HTH's

 

[OneQuikV6]

Thanks! I'll try and report back.

 

[OneQuikV6]

Well..

With all the gains down on the amps, the noise is gone. I isolated the noise to the Targa amp (imagine that...the 1 piece of crap peice in my system) It has (2) different grounds on it. One is the main ground and the other is labeled something else "ground." Can't remember and can't get to the end well enough to read the writing. By unhooking the 2nd ground connection, the noise is gone. I guess I have forgotten what this second ground is, as the amp is 10 years old. ANyway, it works flawlessly now with only the major ground connection hooked up.

Next step is another RF amp to replace the Targa and a set of Quarts in a Q-Logic kick panel. For now, the Infinitys will have to do up front
BTW, the JL's sound TIGHT in the trunk of the T Type. Lovin' it!

 

[zam70]

The second ground (smaller wire) is a source ground. Back in the day you would run a ground to the back of your deck that was connected to this smaller wire. Now days, you don't need it.

 

[OneQuikV6]

Originally posted by zam70
The second ground (smaller wire) is a source ground. Back in the day you would run a ground to the back of your deck that was connected to this smaller wire. Now days, you don't need it.

That was it Definately old school. I had forgotten I had this amp and ran into it while doing the install. Thought I'd just use it to power the rear fill 6x9's. It still sounds decent and I'll keep it until I upgrade rear speakers anyway. Thanks for all the help guys!!