silver00spike said:
Is the HU connected to the Bat as well? Sometimes the ground cables, in the OEM harnesses, are grounded to the chassis.
The headunit is grounded by the harness, which I assume is grounded by the chassis. So I should ground the HU directly to the battery? Should this solve my problem?
silver00spike said:
I always connect every peripheral to the battery. That way I know what my ground is. Also, I ground locally to the chassis as well.
If the amps is still squealling after that, there may be something else going on.
well, I grounded the amp, and reciever to the battery, and still get a whine. It got better, but when its still very audible
1) How old is yor car? More then 10 years ? (are there emi protection in spark distribution?)
2) DO NO CONNECT GROUND DIRECTLY TO BATTERY BUT WITH AS SHORT AS POSSIBLE CABLES TO CHASSIS (the chassis is the best "wire" you can use)
3) Remove the ground connection to the end of signal cable (near the amp) ... in my experience this will be the best solution (if point 1 e 2 don' t make effects).
At the end you can try small 1:1 signal transformer, but I don' t know where to find (installers?)..... this is the quickest solution but is the most expensive.
Hope this will help
🙂
2) DO NO CONNECT GROUND DIRECTLY TO BATTERY BUT WITH AS SHORT AS POSSIBLE CABLES TO CHASSIS (the chassis is the best "wire" you can use)
3) Remove the ground connection to the end of signal cable (near the amp) ... in my experience this will be the best solution (if point 1 e 2 don' t make effects).
At the end you can try small 1:1 signal transformer, but I don' t know where to find (installers?)..... this is the quickest solution but is the most expensive.
Hope this will help
🙂
Spike, read my reply to this on page 1. I'll explain this best I can. This not written in stone and I'm sure some will disagree. Rinox..step 3.. he is suggesting you cut the ground conductors of you RCA interconnects which goes along with what I was saying in the reply. Though I wouldn't cut it, ya don't want your wiring all chopped up. A 100 ohm resistor in series with the RCA ground would work but, thats just a patchup. You want the grounds of the deck and the amp to be as close to one another as possible(ELECTRICALLY!). If the deck were in the trunk, 6" from the amp, both their power ground leads tied together at a single point them the noise wouldn't exist would it(Uh Oh... that'll draw some disagreement)? So wire them as if they were right next to each other. However, the ground lead of the amp must be the path of least resistance back to the battery and then the deck ground tied to the amp ground at the amp(ideally). If it is not, it will find an easier way, like through the RCA signal ground. This large current draw through the RCA ground causes a voltage drop across it, which looks like an input signal to an amplifier. See above or RINOX step 3. So why is it noisy only when the engine is running? Batteries supply DC power, alternators supply raw RECTIFIED AC or in other words DC with lots 'O ripple. When a signal caused by a ground loop appears at the amplifier's inputs....it amplifies it, but not all of it, ONLY AC(!), i.e....music and noise. Most audio amps won't amplify DC(as a whole). While a good battery is supposed to filter this out, a bad one will not be able to as well. Loose connections between battery and alternator may make the ripple worse, possibly creating a EMI/RFI induced noise problem. So now the deck ground and the amp ground are closely tied to one another
and the alternator is makin' all that noise and ripple... Fine. Who cares, as long as they BOTH see that noise on their grounds, etc. Oh and Rinox #2...yes i guess a big enough piece of steel will provide a better common ground than thin copper wires. I scratched out a crappy drawing with paint for ya. Hope this helps. Sorry for rambling. --Nine
and the alternator is makin' all that noise and ripple... Fine. Who cares, as long as they BOTH see that noise on their grounds, etc. Oh and Rinox #2...yes i guess a big enough piece of steel will provide a better common ground than thin copper wires. I scratched out a crappy drawing with paint for ya. Hope this helps. Sorry for rambling. --Nine
Attachments
Problem fixxed.. short in CD player causin it to send the engine noise through the RCA cables, sent it in for warranty n got it back works good now....
(Just a FYI,while i'm thinking about it)
One other thing a friend and I discovered a while ago on his Mazda..
There is a Ground strap from the engine block to the firewall (connecting the chassis to the engine block/battery)
This was the *only* ground between the engine and chassis!
This wire was ~12AWG,and was *MELTED* on both ends!
NOT SUFFICIENT!
We added some more ground straps,and a fat one from the Batt (-) terminal to the fender and 99% of his problems are gone!!!
This might be something to look out for!
I went and cleaned/tightened the existing ground straps on my car,and added one more big one directly from the batt to the frame.
My car already had decent strapping,but I did it for the peace of mind.
One other thing a friend and I discovered a while ago on his Mazda..
There is a Ground strap from the engine block to the firewall (connecting the chassis to the engine block/battery)
This was the *only* ground between the engine and chassis!
This wire was ~12AWG,and was *MELTED* on both ends!
NOT SUFFICIENT!
We added some more ground straps,and a fat one from the Batt (-) terminal to the fender and 99% of his problems are gone!!!
This might be something to look out for!
I went and cleaned/tightened the existing ground straps on my car,and added one more big one directly from the batt to the frame.
My car already had decent strapping,but I did it for the peace of mind.
More noise makers
Guys,
Wow that was a marathon.
Ive had a couple of wonderful noise makers in GM cars.
My least favorite was the electric fuel pump in the damm tank.
Any time that ran, it threw a buzz into most audio electronics from the factory stereo, and the two way radios.
No joy to change either.
The second was the resistance heater that was the rear window defroster.
One day my two way radios just quit, and the FM entertainment set was only able to pick up local stations. Somethign was clearing knocking the heck out of my RF front ends.
Took a while to find, but the control module that ran the rear defroster failed in the 'on mode'. When current runs across the resistor paste on the glass, it acts like a wide band noise jammer.
A miserable thing.
Either way, Im glad it's solved. Lesson learned.
Be safe
Jack Crow in Kuwait
Guys,
Wow that was a marathon.
Ive had a couple of wonderful noise makers in GM cars.
My least favorite was the electric fuel pump in the damm tank.
Any time that ran, it threw a buzz into most audio electronics from the factory stereo, and the two way radios.
No joy to change either.
The second was the resistance heater that was the rear window defroster.
One day my two way radios just quit, and the FM entertainment set was only able to pick up local stations. Somethign was clearing knocking the heck out of my RF front ends.
Took a while to find, but the control module that ran the rear defroster failed in the 'on mode'. When current runs across the resistor paste on the glass, it acts like a wide band noise jammer.
A miserable thing.
Either way, Im glad it's solved. Lesson learned.
Be safe
Jack Crow in Kuwait
The rear defogger? really?
Maybe the controller was a PWM type deal?
I once had a heck of a time with noise in a car audio setup..took me weeks to figure out it was from the "dimmer module" for the lights in the dashboard/gauges/etc...It was some kind of PWM setup,and was noisy as heck!!
Maybe the controller was a PWM type deal?
I once had a heck of a time with noise in a car audio setup..took me weeks to figure out it was from the "dimmer module" for the lights in the dashboard/gauges/etc...It was some kind of PWM setup,and was noisy as heck!!
Noise 101
DJ,
Let's look at the physics of all this.
When a current flows through a resistor made of particles, it makes a series of very small arc's.
Each arc is a tiny wide band rf source. Put a few million of these micro arcs in the space of the rear glass in a Buick. It made quite a racket.
Early microwave jammers were spark gaps in resonent containers.
Something to be said for the method.
The relay in the control module latched shut, and that's why the defroster turned on. I found it when I removed the battery cable and drew a fat spark.
Later dude
Jack Crow in Kuwait
DJ,
Let's look at the physics of all this.
When a current flows through a resistor made of particles, it makes a series of very small arc's.
Each arc is a tiny wide band rf source. Put a few million of these micro arcs in the space of the rear glass in a Buick. It made quite a racket.
Early microwave jammers were spark gaps in resonent containers.
Something to be said for the method.
The relay in the control module latched shut, and that's why the defroster turned on. I found it when I removed the battery cable and drew a fat spark.
Later dude
Jack Crow in Kuwait
Silver,
Me thinks your on the way to results.
First off, in this business you can't trust anything other than your self.
Ive just had a major run around with a set of generator controlers because the manuals lie.
Had to work up my own test tools and procedures. Guess what, my way works and refuses to fail.
So the same deal with our cars.
On my old Buick, the control box said the rear defroster was off, light was out.
Yet the welded contacts in the control relay made the indicator lie. The indicator was tied into the defroster timer, not the output circuit.
The unit was passing current like crazy into the resistor grid. When the key was in and turned on.
So if your defroster is off, and the noise went away, that's a pointer in the right direction.
Unfortunatly there is no easy way to solve this short of scraping the resistance heater and installing a blower motor combination. Then your trading one noise for another.
Good luck dude
Jack Crow
TDY Camp Arifjan, Kuwait
Me thinks your on the way to results.
First off, in this business you can't trust anything other than your self.
Ive just had a major run around with a set of generator controlers because the manuals lie.
Had to work up my own test tools and procedures. Guess what, my way works and refuses to fail.
So the same deal with our cars.
On my old Buick, the control box said the rear defroster was off, light was out.
Yet the welded contacts in the control relay made the indicator lie. The indicator was tied into the defroster timer, not the output circuit.
The unit was passing current like crazy into the resistor grid. When the key was in and turned on.
So if your defroster is off, and the noise went away, that's a pointer in the right direction.
Unfortunatly there is no easy way to solve this short of scraping the resistance heater and installing a blower motor combination. Then your trading one noise for another.
Good luck dude
Jack Crow
TDY Camp Arifjan, Kuwait
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