Alternator noise, have read all posts
Senior Member
Joined: 02-03-2006
Posts: 1,785
From: So Cal
Tuff sell, sounds like you've done everything right. It's hard to say without being able to see exactly were you grounded your amps. But it's obviously coming from the amp ground, since you can pull the rca's and still hear it. Try a different ground point, maybe closer to the battery. As a last resort, no promises, you may have to shorten your negative cable length. Look forward to seeing the pics...
Ng
Ng
Thread Starter
Member
Joined: 04-01-2007
Posts: 90
From: Streetsboro,Ohio
Well after talking to several techs at work and reading and talking with everyone on here, I am going to try a couple of things. 1st I am going to add a ground strap to the grounding plate in the rear by the battery, and jump it to the body. 2nd I am going to add a ground strap from the engine to the body. I will also try moving my amp grounds again if this does not help. I will keep all of you posted.
Thread Starter
Member
Joined: 04-01-2007
Posts: 90
From: Streetsboro,Ohio
Well here is an update, I had the ground straps installed, one from the alternator to the body, and one from the neg batt cable plate to the body. It has reduced the noise but still is not gone completely. As soon as the weather breaks around here I will try moving the ground on my amps. Just curious where do some of you out there have them grounded??
Senior Member
Joined: 03-19-2007
Posts: 670
From: Port Huron, Michigan
I have two LCD screens for the kids on the back of the headrests. They plug into the 12 volt outlet in the back seat area. The screens are getting the same engine whine noise thru their speakers as noted above. Any idea on how to get a better ground when only using a 12 volt plug in cord??
Platinum Member
Joined: 05-09-2006
Posts: 6,805
From: "Upland" Mesa, Arizona
I don't know if this will work..but it's free...so give it a try....
The cord that plugs into the outlet...if you have enough cord, make about a 2 inch coil with the excess. Run the plug through the middle, so the excess hangs on the plug, and plug it in. Sometimes, not all the time, you can create a 'field" that will prevent the interference. Use all the cord possible.
The cord that plugs into the outlet...if you have enough cord, make about a 2 inch coil with the excess. Run the plug through the middle, so the excess hangs on the plug, and plug it in. Sometimes, not all the time, you can create a 'field" that will prevent the interference. Use all the cord possible.
Last edited by Snoopy; May 12, 2007 at 01:25 PM.
Senior Member
Joined: 02-03-2006
Posts: 1,785
From: So Cal
I have two LCD screens for the kids on the back of the headrests. They plug into the 12 volt outlet in the back seat area. The screens are getting the same engine whine noise thru their speakers as noted above. Any idea on how to get a better ground when only using a 12 volt plug in cord??
Ng
New Member
Joined: 06-05-2007
Posts: 10
From: GA
Here let me try and help
This is straight from the MECP study guide
"If the noise persists when the line-level plugs are removed from the amp, then the noise is probably coming in on the power line(though you could have a ground loop between the amp and a bad chassis ground point, or faulty product.) Try moving the location of the power cable away from such items as vehicle computers and stock wire looms. If this does not help, a noise filter can be put on the power line. Be advised, however, that an in-line passive noise filter will always drop the voltage to the amplifier and may limit its performance."
The reason I gave you this info is because you stated that when you unplug the rcas it goes away.
More tips for your ground wires, use star washers when bolting or screwing them to the vehicle the star part will dig into the metal better and provide a better ground than a flat washer.
Use the same size ground as your power wire never use a smaller ground than power but its ok to use a smaller power than ground although I wouldnt.
Use signal grounding areas never have multiple grounds when you can have one that goes for up front at the radio and in the rear for your amps.
Never use the stock ground or power wire provided by the manufacter they tend to cause ground loops because they dont go directly to grounds or battery but thru the fuse box and pick up other accesories.
"Avoid choosing ground points that are secondary body or chassis components that may have the added resistance of tack welds or bolts between the main and secondary parts. A hood, trunk lid, or rear deck are primary examples of secondary body components"
If this doesnt help and your still stumped than I would suggest checking out the12vold.com
Good Luck
Later
Bernie
This is straight from the MECP study guide
"If the noise persists when the line-level plugs are removed from the amp, then the noise is probably coming in on the power line(though you could have a ground loop between the amp and a bad chassis ground point, or faulty product.) Try moving the location of the power cable away from such items as vehicle computers and stock wire looms. If this does not help, a noise filter can be put on the power line. Be advised, however, that an in-line passive noise filter will always drop the voltage to the amplifier and may limit its performance."
The reason I gave you this info is because you stated that when you unplug the rcas it goes away.
More tips for your ground wires, use star washers when bolting or screwing them to the vehicle the star part will dig into the metal better and provide a better ground than a flat washer.
Use the same size ground as your power wire never use a smaller ground than power but its ok to use a smaller power than ground although I wouldnt.
Use signal grounding areas never have multiple grounds when you can have one that goes for up front at the radio and in the rear for your amps.
Never use the stock ground or power wire provided by the manufacter they tend to cause ground loops because they dont go directly to grounds or battery but thru the fuse box and pick up other accesories.
"Avoid choosing ground points that are secondary body or chassis components that may have the added resistance of tack welds or bolts between the main and secondary parts. A hood, trunk lid, or rear deck are primary examples of secondary body components"
If this doesnt help and your still stumped than I would suggest checking out the12vold.com
Good Luck
Later
Bernie
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