dan_seguin90

sorry some asked for more info on headunits.

i got two.
pioneer 5000dvd
and pioneer 6000ub

as far as the big three i has grounded the body to the battery with 0 gauge.
i guess the alternator would be the second and i didnt know i should to that. maybe ill check it out but if i remeeber correctly my alternator is quite hard to reach but will check it out.
what is the third.

godzilla1978

Having 2 runs for power can also cause problems as well.(volage drop=poor performance=noise!) You should always terminate your grounds to one spot. Alson the ground should be as short as possible which means usually somewhere in the trunk. If you also have distrobution blocks make sure the connections there are tight and clean. For grounding in the trunk seatbolts,strut tower bolts or anything like that don't count as a ground. You gotta ground DIRECTLY to the chassis to avoid problems

dan_seguin90

all the grounds were at one place as you could see above. but it hard trhe most noise. not only until i created a ground mania did the noise level go down. the grounds i have are all at 0 ohm or something i had my guys at the local FS instal garage where i used to work double and triple check them for me. they are very good grounds. but i know its no t the power wiring since the things that really affect the noise are done with the rcas and deck. i believe i have fried my groundblock or whatever inside the deck (happens to many new pioneer) but i do not wish to send out for repair since i know i can fix the problem without a new deck. since it has happened to me before. and even if i do get it replaced i will run into the same problem. and have to fix it later so i decided to do it now while my car is in pieces ion my basement.

godzilla1978

I'm not sure about the ground block thing, but I do know that pioneers are sensitive to induced noise(alternator wine).To find out if it's the RCA's try running them outside of the car to see if the noise is coming from something in the car. That may narrow down where the remaining noise is coming from.

danyman

iTrader: (1)

get a noise sniffer lol

zzzzzzz

iTrader: (5)

just get a new car

macguyver

So, why is that? I call BS to that.

How long is your power wire? Unless you are grossly exceeding the constant current draw of your wire (1/0 is CEC rated for 120A with 90 degree insulation), this rarely if ever an issue. Most systems do not even come close to that, and most wiring is rated for up to 600% loading for quite some time.

How long of a trip is it through the chassis of your vehicle, through spot welds (there are no continuous sheets of steel in modern cars), all the way to the battery. The wire for your positive may in fact be shorter than the path via the vehicle's chassis to ground.

You can make a sniffer by removing the the head from a cassette walkman, and extending the wiring and put the head on a stick so you can manipulate it around.

Make sure your engine block to chassis and battery to chassis gorunds are as big as your power wire, or even bigger is better. You may still have noise, as you may have a crappy rectifier (basically diodes) in your alternator.

godzilla1978

About the one piece of sheet metal thing, our MTX rep said the same thing. So I decided to check resistance on the grounds at the chassis in the trunk, for a cable from the amp back to the battery(ran it outside of the car cause I'm lazy and my stuff is already grounded in the trunk) They were the same. So I say it's better to ground as close as possible to 1)Save money! 2)More wire more potential for problems and such. Yes the panels are not one piece but if they were joined together so poorly that they could not provide ground they would not be able to hold the car together or provide any structural integrity. So I say shorter is better!

macguyver

A resistance test is absolutely meaningless. A multimeter sends out millivolts and milliamps as test current. Poor connections, or connections that will not actually pass large amounts of current will not be found this way. I promise you that a joint that reads 0.0 ohms with a multimeter will read something very different at 50, 75 or 100 amps.

DC is not like AC at all. AC will often bridge a poor connection, but DC will not. Even at lower currents, DC will cause a poor joint to heat up, and increse it's ESR quite substantially.

The only 100% guaranteed good ground you will ever have is to have both positive and negative lines run all the way back to their source, both battery and alternator. Anything less and you're banking on a the quality of another's job that really we have no idea how good it is, until there is a problem to fix.

Current flows down the path of least resistance. If you have 14.4V potential to ground at your deck, but you are getting 13.5V at your amp due to current draw, porr gorund or inability of your chosen ground path to pass current, you are going to get circulation of current and voltage along the RCA lines. As RCAs are passing AC, this is where your AC ripple from your alternator is likely to pass. And that 0.9v difference may be more than the signal your deck is producing. The effect of this would be noise in the extreme, but most guys don't have that problem, their problem is more in the microvolt range, but still enough to be annoying. This is why grounding the RCAs can be effective, but not always, to remove any stray voltage on the RCAs between components. This is a "ground loop" and the reason "ground loop isolators" work is to break this physical link with a 1:1 step transformer.

Haunz

iTrader: (3)

This topic always seems to bring out the stupid...




I suggest checking out David Navone - Car Audio Engineering. They have several different devices that will fix a ground loop problem, everytime...