Noise filter and NAV

ZOSO Runner

ZOSO Runner

New member
A strange thing seems to be happening after I installed a noise filter. I have installed a new amp and speakers and am getting the dreaded alternator hum, so I checked all the RCA's to make sure they aren't near any power sources. The other day I installed an inexpensive noise filter made by Metra. This not only did not help with the alternator buzz, but now I am getting the check engine and VSC Trac/ VSC off idiot lights on the dash, and to make matters even worse, the NAV ('05 Camry) is not receiving the vehicle speed and reverse sensor signals.:mad: I guess my question to the group is, how does the noise filter work, would installing this affect the things mentioned? The filter was connected on the + wire lead from the car (I believe it is the yellow wire with a blue stripe). What could have gone so terrably wrong? I checked to make sure all the connections were secure, and still nothing. HELP!!!
 
Register to hide this ad
Hello Z:

A noise filter is noting more than one or more pairs of capacitors and inductors designed to provide a path to ground for only the AC component of what's on the 12 vdc power line.

An alternator noise suppresor should be connected between the Alternator and the battery. Alternator hum or buz comes from the dc output of the alternator that charges the battery. The only difference between switched DC and Battery is the fact that the motor is running and that switched DC is taken on the output side of the ignition switch. By installing the alternator noise suppressor as I stated, grounds the hum or buz at the source. Besides the power input and output, the filter also has a ground tab or wire that's very important. Without the ground connected, there's no place for the noise to go.

From what you wrote, I suspect the filter is not properly installed. As for the other problems, it's hard to believe a noise suppresor would cause that unless it's connected between the wrong wires. I hope this helps. If you explain exactly where and how you installed the filter, I might be able to help more than I have.

Mark
 
Thanks for responding Mark. Your explanation makes sense, albeit a bit technical. I installed the noise filter on the + line that goes to the harness for the radio. It is grounded to the bracket that holds the radio. I am not sure where to install a filter as you described from the alternator to the battery. Is an alternator noise supressor the same as a noise filter?
The other issues have been resolved, I must have loosened the connection of the speed sensor in its harness. That is why the check engine and the other lights came on. I was able to correct this problem and all is well again with the NAV, the dealer was able to track the problem to the speed sensor, but disovered no problem (because I had already fixed the connection) and resest the warning lights. The alternator buzz is still there. When I purchased the noise filter from PepBoys, I went with the less expensive one. Is there a difference in quality, should I have purchased the larger and more expensive one?

Thanks again for you help.
 
Z:

I'm glad I could help. Yes, you're right, I was a bit technical, but you are doing this yourself so technical it has to be I'm afraid. Yes, there is a difference between a noise suppressor and an alternator noise suppresor. Yes, the biggest difference being how much current can go through it. I just bought one for my 4R and I'm about to install it this afternoon. I'll let you know how that goes. Now for more technical stuff.

There are two categories of "noise" you don't want. Alternator noise and EMI. The former is much easier to get rid of with an alternator noise suppresor -- make sure it's rated for at least 60 amps! I doubt you have EMI, but let's make sure. If the hum or buz is a steady frequency or pitch that follows the RPM of the engine; in other words as the RPM increases so does the pitch of the humm, then that's caused by the alternator and the best way to get rid of it is at the source with an alternator noise suppresor. If the noise is more random with pops and clicks and hiss, and you can "hear" your turn signals through your speakers or any other elctronic system like the fan in the AC system, then you have an EMI problem and that's a little tougher to get rid of.

Let me know which you have.

Oh, your other question was about the difference between noise filters. The only difference that matters are how many components it has. The simplest is an inductor in series and a capacitor in parallel. Of course manufacturers also charge you for the plastic box they put it in and the cool markings on the side sometimes, but you should only be concerned with the guts. In this case bigger is usually better because it means more filtering, but lets make sure your problem is really alternator noise first.

If you want, we can exchange email addresses and from there, telephone numbers to make this more efficient because I know you want this noise gone fast!

I'm going to install my supressor now and I'll check back later. Wish me luck too.

Mark
 
Mark, I really appreciate all this information. I love that this forum can be used as a teaching media. My noise is definately the alternator, it does as you describe. It pitches higher as the rpm's go higher. Can I purchase an alternator noise filter from say a PepBoys or other auto parts store, or is it something I need to get from Radio Shack or an electronics supply store? What did you get and from where? Where is the best place to install it? I know I am unloading a bunch of questions at you, but as you can tell the buzz is quite annoying.

Best of luck to you in your installation, let me know what you find out.

Thanks again.
-Christopher
 
Z:

Not a problem with all the questions. I've been there myself pal. Okay the fact that it's alternator noise is a good thing. That should make it easier to fix. Go to PepBoys and see if they have a 12v - alternator noise suppressor capable of handling at least 60 amps. you may want to have them install it too. If they don't have one, I know Crutchfield does for $9.95 + S & H (www.crutchfield.com).

Just out of curiosity, which nav package did you purchase from OEM Value? If you got package number 1, where did you mount the external amplifier? I have a hunch... maybe. Keep that noise suppressor you have. It still may come in handy.

Can you describe the noise suppressor to me in more detail? how many wires in and how many wires out and what color are they? Also, is the case metal or plastic?

I started installing my alternator suppressor but my daughter called before I had all the insulation off of the wire bundle. It didn't get done today, but I'll try again tomorrow.

Mark
 
I have the '05 Camry NAV. I mounted the external amp behind the upper glove box using an existing bracket, that I think must be used for the optional CD changer. In addition to that I installed a Rockford Fosgate amp under the drivers seat.

Man, 60 amps? I went to Radio Shack and they had one capable of handling 20 amps, and that was like $21. But it did not say anything about it being an alternator noise supressor, I think it was just a noise filter. The one that I have has one red wire going in and a red and a black wire comming out. It is made of plastic and cost about $10 at PepBoys. When I connected it the first time, I cut the + wire going to the radio harness, it was a yellow with a blue stripe wire. I connected the single red wire to the wire comming from the car, and connected the other red wire to the wire going to the harness. The black wire was grounded to the camry amp. Does that make any sense?
 
Christopher:

Yes, that makes sense about the noise filter. Just make sure the black wire is really well grounded because that's where the filter sends the noise -- to ground -- more about this at the end.

There are two paths for the noise to travel in order to get into your stereo system: the head unit power line and your amplifier's power line. Since you've already filtered the head unit's power, you may want to do the same thing with the amplifier power line. It's not necessarily a difinitive test, but does the humm increase when you increase the volume of the music? Again, it doesn't prove it's not in the amp if it doesn't, but it does verify the noise is in the amp if it does. Now that I've totally confused you, filter the amp with another filter just like you bought for the head unit.

For future reference, in order to filter noise from a stereo like you're doing, always work back from the symptom. In this case, you can hear the noise so filter the amp. If you still hear it, filter the head unit. If you still hear it, filter the alternator.

My approach is to filter out the noise at the source. That's why I'm starting with an alternator noise suppressor. Really though, we're doing the same thing, allowing the DC to pass through the filter(s) and ground the AC noise portion to ground.

It sounds like you installed the filter correctly. Just don't ground the filter to the chassis of the thing your filtering like the head unit or amp. I'd find a good ground point right on the frame or body of the car itself. Also don't wrap the bare wire around a bolt and tighten it down. Take the time to crimp on a lug washer of the correct size and maybe even add a spider washer to get a good bite into the metal. Technically speaking your trying to make a physical connection into an electrical connection so do a good job with the ground.

Mark
 
Christopher:

After considering the mod it would be to install the alternator noise suppressor (ANS) between the alternator and battery, I decided I couldn't do it. My Air Force electronics training will not allow me to cut a 00 gauge wire and install a unit with 10 gauge wire in series. I know people do it, but I can not. Instead, I found a new place to install it.

On top of the driver's side - front wheel - under the hood, you'll find the main fuse block. On the back - right side of it, is where the power comes in directly from the alternator. If you take the cover off of this fuse block, you'll see the connection is called the head and that's where I'm going to install the ANS today.

I plan on taking digital photos of the mod and posting them if you still need to filter some alternator noise. Please let me know.

Mark
 
OH man that would be GREAT!!!! I am going to check again on where I laid out my RCA's to see if I can alieve any of the noise. I have a feeling I will need to do the alternator filter mod anyway though. Good luck buddy!!!
 
Christopher:

I checked with Crutchfield and I was correct, the ANS is not big enough to carry the load that our 4 Runner alternators can. Our alternators are rated for 150 Amps. The alternator itself has a 140 amp fuse in the main fuse block so I didn't want to install a 60 amp noise suppresor in series -- it would not have lasted. To make a long story short, I order two more and plan to install them in parallel (60 A X 3 = 180 Amps). I know that will hold.

I went to Ace hardware and bought an "L" bracket and some steel nuts and bolts for a mounting idea I have.

I'll keep you in the loop, promise.

Mark
 
You're the man Mark!!! I hope this all works, the hiss is persistant. I noticed that there is a hiss whether the engine is on or off, and the alternator whine when on. The hiss will diminsh if I turn the gains way down on the amp, but this defeats the purpose of the amp. Is this because our NAV doesn't have a built-in filter? Shouldn't the one that I installed on the radio + taken care of that? Let me know what you think.

Thanks....
 
Chistopher:

Check these links out. They may help. I wasn't aware of a hiss problem too. That's a whole different story because you can't filter that out -- you have to track it down and fix the problem causing it.

http://www.crutchfieldadvisor.com/ISEO-rgbtcspd/learningcenter/car/noise

http://ccs.exl.info/noise.html

http://www.crutchfieldadvisor.com/S-hu1omyjdBGv/learningcenter/car/noise.html

I think these will keep you quite busy with easy ways to track down the hiss. I suggest if you're not alreay using them, try twisted-pair RCA cables. All amplifiers produce hiss or "white noise" but you can reduce it as long as there's nothing wrong with your amp.

Good luck.

Mark
 
Alternator Humm w/ Nav System

Christopher:

No Joy dude! I did the mod and it made absolutely no difference to the noise I'm hearing. Have you had any luck yet?

I have to open everything up again anyway in a couple of weeks to install my microphone system and the Toyota XM Receiver. When I do, I'm going to replace and extend the two plugs and wiring going to the external amplifier. I had a stereo place install another XM receiver I had and they spliced right into those wires. I'm also going to try to find a better location for the amplifier that's closer to the nav unit.

You may want to try running a fat (8 gauge or more) wire from the nav head unit chassis directly to the metal case of the amplifer and see if that makes the noise change. I'm now thinking we may have a ground loop problem.

Mark
 
Mark:

Sorry to hear about your less than successful mod. I have had limited success in lessoning the hiss. First off thanks for the links, they helped out a bunch. I purchased some new RCA cables from Monster Cable, MicroXLN in 10 ft lengths. I also turned down the gains on my amp, the combination of the two has helped a bit, but there is still the alternator hum, even when the radio is turned off and I'm just driving around. I also noticed that when I turn the fan on full blast, there is a high pitched whine.

I was also thinking that there is a ground loop problem, especially after reading this thread- http://www.toyota-4runner.org/showt...perpage=20&highlight=ground loop&pagenumber=2. Tell me what you think after reading it. Hopefully this is the answer to our problem. I would have tried this already, but I am tired of disonnecting the battery, taking apart the dash/radio, and having to reset everything. I think I must have done this like a million times already. But if you have success with it, then one more time won't kill me. Good luck, keep me posted buddy!!!
 
IT WORKED ! ! !

Christopher:

It worked! ground wire (10AWG) from the Nav HU chassis to single point ground in front of the center console. Then another ground wire from the amp's brown (chassis ground) wire to the same main ground point.

My system is very quiet -- no buzz! I love it. I also installed my microphone system for voice control (very cool) and a 2005 Solara XM Receiver. W O W ! ! ! Take care.

Mark
 
Great!!!

Congrats, I will fix mine this weekend, I have only one question. Did you cut the brown wire and then connect the extension wire to the console ground from the wire going to the truck, or the wire going to the harness and amp?
 
Re: Great!!!

ZOSO Runner said:
Congrats, I will fix mine this weekend, I have only one question. Did you cut the brown wire and then connect the extension wire to the console ground from the wire going to the truck, or the wire going to the harness and amp?
Click to expand...

Neither! I stripped about 1/2" of insulation off of the brown wire that goes from the stereo wiring harness to the stereo amplifier (large plug). I then soldered a 10 AWG wire onto the brown, amplifier chassis ground wire, to a common ground point in front of the center console, right. This is also the same ground point I connected another 10 AWG wire up to the Nav Head Unit chassis with an eyelet connector. No Buzz!

Let me know what happens with your truck!

Mark
 
AAAGGG!!!! No Luck....

Mark, I did not have any luck with my truck. I connected a wire from the bracket of the the HU to the ground point at the front console. Then I tapped the brown ground wire located between the camry amp and the HU and connected it to the same ground point in the console. The buzz is still there. I then tried tapping the ground wire located on the camry amp going to the truck, still a buzz. I also just tried connecting a wire from a mounting point on the side of the amp, no luck. The wierd thing about that was that I had the HU powered up once and was holding the camry amp and it seemed to periodically stop the buzz, depending on where I was touching the amp.

My setup is as follows, I have the camry NAV connected to the small camry amp, I also have a rockford fosgate amp that is grounded to the frame of the truck under the drivers seat. The signals to the amp are through rca cables that are connected through typical rca-wire connection that are connected to the truck speaker connection at the small harness to the camry amp. They have built-in noise filters that are grounded at the same center console grounding point (it is very crowded with ground wires there).

I am so frustrated, I thought for sure this would work. What do you think? What am I doing wrong? I checked to make sure there is contact at the wire taps, and good connection at the console ground. Ugh!!!
 
You must log in or register to reply here.

Members online

Total: 233 (members: 4, guests: 229)

Forum statistics

Threads
278,306
Messages
3,554,046
Members
248,016
Latest member
Advally Service

Share this page

Trending content

Back
Top