route your Plus and Minus/earth direct from distro block to the Headunit......from the same point your amps are connected to the power supply......

 

Measure resistance from the black wire to chassis. Sounds like bad grounding, if possible ground HU at the same place as amps.

Tapaaatalk!!

 

LBaudio and Hanatsu, thank you for the replies but my head unit ground wire is not the problem. Head unit ground wire runs all the way back to a distribution block with my amps ground wires. The noise issue im experiencing is OBVIOUSLY coming through my antenna wire. I know this because when playing a cd or ipod and I dissconnect my antenna, the noise goes away. So right now I can enjoy my cds and ipod noise free with my antenna dissconnected but can not listen to radio stations because of the annoying alternator whine.

But the point of this thread is for responders to share their findings who have also experienced alternator noise through their antenna port and how they solved it.

 

Perhaps an isolator on the antenna wire would reduce the noise, but I don't know if any are made for that connection. I figure one could be spliced in-line.
The isolator would probable be the most effective close to the head unit.
Also, I don't know whether the bandwidth for isolators would end up attenuating the radio frequencys. It is just an idea.

Sent from my HTC6500LVW using Tapatalk 2

 

Three units in a row demonstrating the same issue indicates that the problem is in the vehicle, not the product. Sounds like the antenna wire in the truck might be grounded out someplace and/or the chassis ground resistance is too high, like Hanatsu said.

 

American International AS100 Antenna noise filter at Crutchfield.com

In the case of my vehicle, I understand the problem originates with my vehicle. But my request for other member's similar experiences was to answer a few questions.

First, is it normal for a head unit to complete its power circuit through its chasis (aka. Ground out without its black or (-) wire)?

Second, if this is normal, is there a way to dissconnect a head units ground from its chasis? Such as, a wire to clip or hidden switch?

Third, Is it normal for a car antenna to be part of a vehicles "body" ground system? If so, would an aftermarket antenna (one that doesn't connect to the car body's ground) be a good solution for my situation?

Fourth, do thesse things in the above link do any kind of good for the situation?



Again, thank you kindly for any advice!

 

Yes, it is normal for the chassis of the radio to have a ground path to the vehicle through the antenna. Typically though it is not normal for that to be the path of least resistance. In this case it seems, that condition is reversed for some reason. If there is a way to de-couple the power supply of the radio from the chassis of the unit, I have not heard about it.

A filter like that may very well solve the issue, or at least attenuate the noise to an inaudible level. Replacing the antenna altogether or just leaving it disconnected may also be a solution.

 

classic ground loop problem. you have a difference of potential from your amps/procs than you do from the HU. so you get whine.

reground the HU, so you are not using the ANT ground as the primary ground. If that doesnt solve it, then look into a good quality GLI.

 

Currently, I am not using the antenna at all and the normal "Black" wire ground is connected. The problem is, if I plug in the antenna, I get the altenator noise no matter what source is being used (CD,Ipod, SiriusXM, etc.). So Im looking for a way to reconnect the radio antenna and eliminate the noise issue.

 

Has anyone else out there had this problem that they can share their experiences with? How did you solve the issue

 

Ground loops are quite common, solving them can stump even a seasoned veteran, lol.

Try this, just as a test. Take a piece of wire and connect only thr ant center conductor. Radio work?

As mentioned before, try re grounding the hu or get a GLI.(sometimes the only solution )

sent from my phone using digital farts

 

I've never had the problem and I'm no EMC/RFI expert.

Nevertheless, I've worked with EMC/RFI experts and I recall what my installer did just so I would not have your problem.

Nearly ever EMC/RFI expert I have worked with say add more or make sure the grounds present are proper. Ground should be the vehicle chassis (lowest potential) not the negative post on the battery (although component engineers beg for the battery).

In my car the radio chassis is a ground plane and the antenna has a ground connection to chassis at the point the antenna is attached to the car. My batteries and amps all ground to the same point as the antenna.

Whenever I've had a noise issue, it's normally fixed by tightening this joint of grounds.

I would check your antenna install, make sure it's grounded properly, and make sure all your ground connections are good.

 

sounds to me like the vehicle might have a factory antenna amplifier and upon installation of the new deck/DVD the ground to the amplifier may not have been re-connected?

so when this amplifier uses the shield of the coax as the ground at the radio, it's allowing a ground path interference that's set up due to the unequal potentials of the fender and the under-dash locations.

You can hazardly ground through your pre-amp RCA's if there is no other ground through the chassis or the antenna, so I wouldn't disconnect both of those and see if it still works at full power. (blow out your pre-amp)

 

Has anyone else out there had this same problem that could share any insight?

 

I know this is an old post but I'm having the exact same problem alternator whine no matter what input I'm in but if I disconnect the antenna it goes away has anyone figured out how to solve this problem

 

You have to ground your head unit. I run a ground and power to my head unit from my distribution blocks in the back.

 

That doesn’t get around the fact there’s a potential being generated between one earth and another, I would try earthing both the antennae where it contacts the car body and also the radio both back to the same point, that way you have no way for a potential difference to occur, everyone saying just earth the radio back to the same spot as the amps is missing the fact that the aerial takes an earth from the chassis also, if this is bad it needs remedying, was common place in days of old with wing mounted pull up aerials to have a problem with a bad earth at the aerial base causing noise issues 👍🏼

 

If you don't have a power antenna and you connected a blue wire to your aftermarket harness, this will cause noise and look like the antenna is causing it when you unplug it and it goes away.