hu with bad ground

hi all, i tried fixing a amp a few months ago, but became unsucessful after engine noise... =[ I tried: 1. connected ground of amp to bare metal on chassis (didnt work) 2. power wires running opposite to speaker wires (didnt work) 3. connected my mp3 player with the rca's to the amp (no engine noise!) Does this mean: 1. My amp has a good ground? 2. and my head unit has a bad ground(i used the connections which were already there[oem ones])? Could someone pls clarify, becuase I dont want to open up the car and everything without a resolution

Pioneer head unit?

I am getting the same result on my Eclipse CD-8445. I even ran ground from the headunit to the trunk where the amplifiers ground to. I am wondering if: 1. my alternator is going out? 2. if there is something wrong with my Eclipse headunit. NOTE: I also have 8 gauge grounds in my engine bay for grounding the motor to car. Would this create noise?Mark "Hamzter" Cinense

1991 Infiniti G20 w/JDM SR20DE

Eclipse CD8445

MTX Thunder 684

Polk DB6750

Polk DB6500

Optima Red Top in the Trunk

panasonic head unit =]

Both of you can try this anyway. Sounds like your RCA jacks have lost their ground reference. Remove your radio from the dash, take a couple feet of small wire, strip both ends of it. Ground one end to the same place your radio is grounded, then with your engine running and engine noise a blaring, touch the other end of the wire to the shield of your patch cord. That would be the metal part you can see when the cable is connected. This should make a pop and the noise should go away. If this works let me know and I can assist you in repairing your radio.

right on man... I will definitely look into that... However, I think I have a bigger problem at the moment... I think my voltage regulator is out... soooohhhh... that means my alternator is out and therefore a possibility of why my engine noise is bad... Any care to comment on that? this is the 3rd one I have had to replace in the last 12 months. anyone know why?Mark "Hamzter" Cinense

1991 Infiniti G20 w/JDM SR20DE

Eclipse CD8445

MTX Thunder 684

Polk DB6750

Polk DB6500

Optima Red Top in the Trunk

     When you rev your engine, do your headlights get really bright? And why do you think your regulator is out?

got a voltage drop on my gauge while I drive. Took it to Autozone and the current was registering at like 177 amps at 2000 rpms. would this cause noise in my headunit/audio system?Mark "Hamzter" Cinense

1991 Infiniti G20 w/JDM SR20DE

Eclipse CD8445

MTX Thunder 684

Polk DB6750

Polk DB6500

Optima Red Top in the Trunk

       Your regulator's only purpose is to keep the voltage from exceeding a certain voltage. Usually between 13.8 and 14.2 volts. If your voltage is dropping below this, your alternator is likely the culprit. When you said AutoZone said 177 amps at 2000 RPM,are you saying that is how much current your alternator is putting out?

i am an idiot wrote:        Your regulator's only purpose is to keep the voltage from exceeding a certain voltage. Usually between 13.8 and 14.2 volts. If your voltage is dropping below this, your alternator is likely the culprit. When you said AutoZone said 177 amps at 2000 RPM,are you saying that is how much current your alternator is putting out?

that is correct. while driving, after releasing my foot from the accelerator my voltage goes down to 12.5 then climbs back up to about 13.4-13.5 volts. That seems a bit low. Also without the sound system on, I can hear what appears to be a generator whine while I accelerate. After researching last night I stumbled across information that indicates what could be killing my re manufactured alternator. It seems it could very well be the affects of heat from a header that I installed about a month or 2 after the new JDM motor was installed. The alternator was replaced back on August 31, 2006. The battery was replaced January 2007. It seems like everything was working fine up until last week. I have a new one coming in tomorrow and it is one made for a 2000-2001 Nissan Sentra that puts out about 100 amps. Hopefully this rebuilt one from Auto Zone will last me until I can get an OEM reuilt equivalent in place.Mark "Hamzter" Cinense

1991 Infiniti G20 w/JDM SR20DE

Eclipse CD8445

MTX Thunder 684

Polk DB6750

Polk DB6500

Optima Red Top in the Trunk