high ground resistance
Yankee
Joined: Oct 2003
Posts: 3,599
I do not mean to be an *** but in an energized system you should be measuring voltage or current NOT resistance... the same information is presented just without the option of blowing up your meter
The ground issue is there when the car is off or on, but the only time you can hear alternator whine is ... when the engine is running.
the ground issue can be: quality of the HU ground, quality of the amplifier ground, quality of any EQ, DSP or line driver in the system. Other items to cause a SYSTEM ground (you have to remember all these things are connected or inter related) a signal RCA that has lost ground, a connection to a speaker that is touching the frame, even the antenna connection (the amplifiers body may need grounding and may be a safety issue).
There is also a posibility that something else in the vehicle has this issue and is dicking up the entire vehicle, this would have showed up in the factory setup. This could also be water intrusion but then it would happen primarily when it rains or you go through a car wash.
1)try a different RCA or ground the OUTER ring of the RCA plug to see if it is the RCA.
2)I am coming to the conclusion that Yuli is right to always run + and - power to the amp and not use the frame.
The ground issue is there when the car is off or on, but the only time you can hear alternator whine is ... when the engine is running.
the ground issue can be: quality of the HU ground, quality of the amplifier ground, quality of any EQ, DSP or line driver in the system. Other items to cause a SYSTEM ground (you have to remember all these things are connected or inter related) a signal RCA that has lost ground, a connection to a speaker that is touching the frame, even the antenna connection (the amplifiers body may need grounding and may be a safety issue).
There is also a posibility that something else in the vehicle has this issue and is dicking up the entire vehicle, this would have showed up in the factory setup. This could also be water intrusion but then it would happen primarily when it rains or you go through a car wash.
1)try a different RCA or ground the OUTER ring of the RCA plug to see if it is the RCA.
2)I am coming to the conclusion that Yuli is right to always run + and - power to the amp and not use the frame.
Last edited by JohnVroom; Nov 30, 2008 at 08:28 AM.
Thread Starter
50 Watt CAFz'r
Joined: Nov 2008
Posts: 63
Silly me, i never did measure the voltage 
Just to clarify - I have tested with the amplifier remote turn on jumped to the 12V on the amp to simplify the tests.
amp ---> speaker connected to left output/or right doesnt matter,ignition off. get small amount of buzz, only enough to hear through tweeter with ear close.
Ignition on - more noise but through mids too and i dont need to be close to the speakers at all.
Car running - amazing amount of engine whine and pops with brake pedal, fan turn on/off, basically anything electrical toggled.
If RCAs are connected the noise gets VERY LOUD. Tried grounding the outer RCA, no difference - this is whether the RCAs are connected to the HU or not. Even tried different RCAs over carpet direct to HU. Hell ive even REMOVED the deck completely from the electrical and no change.
Run ground right to battery - 8ga, no change.
Grounded body with 1 length of 4ga, and 1 length of 1/0. Grounded Engine with i length of 4ga - no noise change.
Changed Battery with newer, fully charged one - no change.
Maybe that will clarify anything that i didnt explain clearly - or just confused the hell out of everyone, LOL
Just to clarify - I have tested with the amplifier remote turn on jumped to the 12V on the amp to simplify the tests.
amp ---> speaker connected to left output/or right doesnt matter,ignition off. get small amount of buzz, only enough to hear through tweeter with ear close.
Ignition on - more noise but through mids too and i dont need to be close to the speakers at all.
Car running - amazing amount of engine whine and pops with brake pedal, fan turn on/off, basically anything electrical toggled.
If RCAs are connected the noise gets VERY LOUD. Tried grounding the outer RCA, no difference - this is whether the RCAs are connected to the HU or not. Even tried different RCAs over carpet direct to HU. Hell ive even REMOVED the deck completely from the electrical and no change.
Run ground right to battery - 8ga, no change.
Grounded body with 1 length of 4ga, and 1 length of 1/0. Grounded Engine with i length of 4ga - no noise change.
Changed Battery with newer, fully charged one - no change.
Maybe that will clarify anything that i didnt explain clearly - or just confused the hell out of everyone, LOL
Last edited by aussie1978; Nov 30, 2008 at 10:41 AM.
Guest
Posts: n/a
I do not mean to be an *** but in an energized system you should be measuring voltage or current NOT resistance... the same information is presented just without the option of blowing up your meter
The ground issue is there when the car is off or on, but the only time you can hear alternator whine is ... when the engine is running.
the ground issue can be: quality of the HU ground, quality of the amplifier ground, quality of any EQ, DSP or line driver in the system. Other items to cause a SYSTEM ground (you have to remember all these things are connected or inter related) a signal RCA that has lost ground, a connection to a speaker that is touching the frame, even the antenna connection (the amplifiers body may need grounding and may be a safety issue).
There is also a posibility that something else in the vehicle has this issue and is dicking up the entire vehicle, this would have showed up in the factory setup. This could also be water intrusion but then it would happen primarily when it rains or you go through a car wash.
1)try a different RCA or ground the OUTER ring of the RCA plug to see if it is the RCA.
2)I am coming to the conclusion that Yuli is right to always run + and - power to the amp and not use the frame.
The ground issue is there when the car is off or on, but the only time you can hear alternator whine is ... when the engine is running.
the ground issue can be: quality of the HU ground, quality of the amplifier ground, quality of any EQ, DSP or line driver in the system. Other items to cause a SYSTEM ground (you have to remember all these things are connected or inter related) a signal RCA that has lost ground, a connection to a speaker that is touching the frame, even the antenna connection (the amplifiers body may need grounding and may be a safety issue).
There is also a posibility that something else in the vehicle has this issue and is dicking up the entire vehicle, this would have showed up in the factory setup. This could also be water intrusion but then it would happen primarily when it rains or you go through a car wash.
1)try a different RCA or ground the OUTER ring of the RCA plug to see if it is the RCA.
2)I am coming to the conclusion that Yuli is right to always run + and - power to the amp and not use the frame.
just so u know the extent of what i went theu, i ended up using 3 diffrant groups of rcas, with and without eq, at least 10 diffrent head units, 4-5 diffrent amps, grounds....well, i dont know how many ties i re-did these all with big gauge wire.
i also had 5-7 batteries in the trunk, hooked up to those, AND tried running right from front batt, screwed down, and not screwed down, my line driver was ran with 10, 8 then 4 gaue with no change, power and ground, as well as my headunits where all run with 10, then 8, then finally i gave up and ran 4 gauge, and nothign changed.
i changed speakers out, ran all new wires from speakers to amp on oposite side of power, did this twice, first time i figured i pinched a wire, took it all out...nothin, tried going from amp to speakers and deck to speakers....all did it, with at least 10 decks.....i even ran rcas down the middle over seats to no avail
i even had the amps sent in for repairs....and im using the same amps, eq right now in my new car, not a hint of noise....same rca's and component set too...weird
this was making noise car off as well, when the car was on it just got a bit louder and would have very slight alt wine....but most of the noise was there with the car off, ignition on.
anyways, just thought id let u know what i had to go thru, so u could understand more
Thread Starter
50 Watt CAFz'r
Joined: Nov 2008
Posts: 63
wow.... that sucks man. I just bought a newer car and hopefully will fix this annoying problem, LOL
Ill stick to Deck power for now and wait a while for it to get warmer (spring time?) as i dont have a heated garage to work in. Dont worry, ill be resurrecting this thread then!!!
Anyhoo, my newer car - 98 sunfire - needs some work on the stereo as its all stock and i can get away with doing this pretty quickly, lol.
Appreciate the time and help on this guys!!
Ill stick to Deck power for now and wait a while for it to get warmer (spring time?) as i dont have a heated garage to work in. Dont worry, ill be resurrecting this thread then!!!
Anyhoo, my newer car - 98 sunfire - needs some work on the stereo as its all stock and i can get away with doing this pretty quickly, lol.
Appreciate the time and help on this guys!!
50 Watt CAFz'r
Joined: Sep 2007
Posts: 259
try this . take your volt meter and ground it to the battery, touch the casing of the alternator with the positive. try this with the van off, key on and running. it sounds like the alt. has a internal short. the alt. always has live power going to it. you could also disconnect the alt. and turn the stereo on and see if it changes. fords have a clip on the top of the alternator with 2 8 gauge wires running to the battery. they get hot and melt and often catch fire when not cared for. the manufacturers of alternators reccomend you change the ford pigtail EVERY time you change the alternator. the pigtails are available at partsource. so try unplugging the alt. and turn on the tunes with the engine off. i wanna see what happens. the plug you want to unplug is 2 black w/orange stripe. in 96 on aerostar they started changing the alternators, yours may have one yellow w/ white stripe. witch is a 120amp gen 3 alt. they've been prone to internal failure.
Last edited by turboeeyore; Nov 30, 2008 at 04:52 PM.
Yankee
Joined: Oct 2003
Posts: 3,599
So that was important if the spare amp performed the same as your amp then the amp is not the problem for sure... just everything else.
-try this feed the amp directly from a MP3 player, or a CD diskman.
- I think you tried running power directly from the battery (if not give it a go OR use a spare battery I always have one or two in the garage)
- The alternators output may be noisy (old?) a capacitor might help if the issue is DC ripple/ noise
- have you tried an RCA noise filter?
-try this feed the amp directly from a MP3 player, or a CD diskman.
- I think you tried running power directly from the battery (if not give it a go OR use a spare battery I always have one or two in the garage)
- The alternators output may be noisy (old?) a capacitor might help if the issue is DC ripple/ noise
- have you tried an RCA noise filter?
Thread Starter
50 Watt CAFz'r
Joined: Nov 2008
Posts: 63
sorry i didnt mention that the other amp did the same thing - i did it on the first of dec. When i tried the new amp i also tried the noise filter on the rca... still no help. Still waiting for a good day to go outside and try some of the suggestions though, 100km winds and below zero really sucks for outside work, lol.
